REACH Practical Guide on Exposure Assessment and

Transcription

Communication in the Supply Chains
Part IV: Supplement Exposure Estimation
June 2010
Copyright
Copyright © of CEFIC (AISBL) and VCI e.V., reproduction is authorised, except for commercial purposes, provided that the source is mentioned and acknowledged. CEFIC and VCI claim no copyright
on any official document, such as the REACH guidance documents (whose abstracts may be used in
this publication) or information provided by the EU Institutions and ECHA.
Disclaimer
The information given in this REACH Guidance is intended for guidance only and whilst the information is provided in utmost good faith and has been based on the best information currently
available, is to be relied upon at the user’s own risk. No representations or warranties are made with
regards to its completeness or accuracy and no liability will be accepted for damages of any nature
whatsoever resulting from the use of or reliance on the information. This does not apply if damage was
caused intentionally or by gross negligence by CEFIC or VCI or by parties assisting them.
Important note to the reader
This document has been prepared by a VCI working group as part of the joint Cefic/VCI
project to develop tools and guidances for industry – in respect of Chemical Safety Assessments, Chemical Safety Reports and Exposure Scenarios.
It is Part IV of the REACH Practical Guide on Exposure Assessment and Communication in
the Supply Chains. It describes the status of development as per Q1 2010. Many activities,
both in industry working groups as within ECHA are still ongoing. The guide is therefore not
to be regarded as complete, but as a status overview.
The Practical Guide comprises several parts. An overview is given in the preface of Part I.
The structure and the contents of the REACH Practical Guide are described on the following
web sites:
VCI: http://www.vci.de/default~cmd~shd~docnr~125022~lastDokNr~102474.htm
All related documents can be downloaded from this site. In addition you find here information
on related issues and actual developments.
CEFIC: http://cefic.org/templates/shwPublications.asp?HID=750
June 2010
REACH Practical Guide / Part IV: Supplement Exposure Estimation
Communication in the Supply Chains
Part IV: Supplement Exposure Estimation
Table of Contents
1
Occupational exposure estimation
1
1.1
1.1.1
1.1.2
1.1.3
Aim, basic concepts and main determinants of occupational
exposure assessment and risk characterisation
Routes of exposure
Approaches to exposure estimation
Determinants of exposure
1
1
2
3
1.2
1.2.1
1.2.2
1.2.3
How to assess occupational exposure
Use of measured data
Sources of measured data
Criteria and selection of appropriate measurement data
3
4
5
5
Inhalation exposure
5
Dermal exposure
5
Use of exposure estimation tools – Tier 1
7
ECETOC Targeted Risk Assessment (TRA)
7
1.2.4
EMKG Exposure assessment tool
16
Use of exposure estimation tools – higher tier
20
Stoffenmanager
20
RISKOFDERM calculator
24
Other tools
28
1.2.6
Efficiency of risk management measures (RMMs)
28
1.3
1.4
1.5
Risk characterisation
Communication of the results in exposure scenarios
References
29
29
30
2
Consumer exposure estimation
32
2.1
Aim, basic concepts and main determinants of consumer exposure
assessment and risk characterisation
32
How to estimate consumer exposure
34
34
1.2.5
2.2
2.2.1
Inhalation exposure
35
Dermal exposure
36
III
REACH Practical Guide / Part IV: Supplement: Exposure Estimation
June 2010
Oral exposure
41
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
Refinement of consumer exposure estimation
Combined uptake
Special case: Humans exposed indirectly via the environment
43
52
57
58
58
2.3
2.4
2.5
Communication of the results in exposure scenarios and scaling
References
58
60
61
3
Environmental exposure estimation
63
3.1
Aim of the environmental exposure estimation and risk
characterisation
Approaches to environmental exposure assessment
Release estimation
63
64
65
Determinants of release
66
How to assess release / emissions to the environment
67
Waste water treatment
69
Distribution and fate processes in the environment
Exposure estimation including derivation of PECs
70
71
71
Calculated PEC values
72
Calculated versus measured PEC values
74
Risk characterisation by comparing PEC/PNEC
75
Quantitative risk characterisation
75
Qualitative risk characterisation
77
3.2.5
3.2.6
3.2.7
Exposure estimation tools – Tier 1
Other tools for environmental exposure estimation
78
80
81
3.3
3.4
Scaling related to environmental exposure
References
81
83
4
Appendices
85
4.1
4.2
4.2.1
Appendix to Chapter 1: Occupational exposure estimation
Appendix to Chapter 2: Consumer exposure estimation
Default values
85
88
88
4.3
Appendix to Chapter 3: Environmental exposure estimation
89
3.2
3.2.1
3.2.2
3.2.3
3.2.4
IV
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1
1.1
Occupational exposure estimation
Aim, basic concepts and main determinants of occupational exposure
assessment and risk characterisation
This general introduction describes some of the basic ideas behind occupational exposure
estimation and risk characterisation (e.g. routes and determinants of exposure), while the
more detailed issues (e.g. application and evaluation of commonly used exposure assessment tools) will be dealt with in subsequent sections.
1.1.1
Routes of exposure
Occupational exposure occurs mainly by inhalation and dermal contact (i.e. uptake through
the skin). Inhalation exposure may take different forms. For example, solids may become
airborne in the form of dust, while a volatile liquid may evaporate and thus generate vapours.
The properties of the substance (e.g. dustiness in the case of solids and vapour pressure in
the case of liquids) are therefore crucial determinants for the exposure estimation and are
generally required by exposure estimation tools (see below).
Although often neglected, dermal exposure may in some cases even be more important than
inhalation exposure. In practise, potential dermal exposure (i.e. the amount of substance on
the surface of (protective) clothing and the exposed skin surface) and actual dermal
exposure (i.e. the amount of substance on the skin available for uptake into the body) are
two ways of measuring dermal exposure.
For substances, which predominantly exert local effects such as skin or eye irritation and
corrosion and skin sensitisation, it may be difficult to quantify these effects and to derive
DNELs for these endpoints. In this case, quantitative dermal exposure estimation may not be
meaningful and a qualitative risk characterisation should be carried out to identify suitable
risk management measures. For example, protective gloves will certainly be worn when
handling a corrosive substance so that exposure will be minimised. A quantitative assessment of the exposure will then not be needed.
In other circumstances dermal contact can be excluded due to the operational conditions of
use. If, for example, the operating temperature of an installation would immediately lead to
burns upon skin contact, it can reasonably be assumed that no dermal contact to substances
processed in this installation may occur.
In contrast to the impact area of consumers, oral exposure (swallowing of the substance) is
less relevant at almost all workplaces and is not further discussed below. Although oral
exposure may occur, e.g. by mouth contact with contaminated work wear, it is generally
controlled by simple good hygiene practices (such as separate eating and drinking facilities,
washing facilities etc., e.g. as laid down in the German “Technical Rule for Hazardous
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Substances 500: Protective measures: Minimum standards” (TRGS 500)). Such practices
are considered to be usually in place on the basis of national occupational safety and health
legislation.
The exposure estimation usually results in an external exposure value:

Inhalation exposure: concentration of the substance in the air (in mg/m3 or ppm, usually
full shift (8 h) averages)

Dermal exposure: amount of substance on clothing and exposed skin surfaces (i.e.
potential dermal exposure; measured actual dermal exposure data may be available in
a few cases). The unit of exposure may vary, e.g. µg/cm2 x h or mg/d.
It is evident that the result of the exposure estimation will not only depend on the properties
of the substance but also on the operational conditions of use and risk management
measures (RMM) in place. These issues will be dealt with below in the context of a
discussion of the tools for exposure estimation.
1.1.2
Approaches to exposure estimation
Generally, relevant information on the exposure situation and on suitable risk management
measures should be available (and should be used for registration purposes) for hazardous
substances from assessments of risks made within the framework of the Council Directive
98/24/EC (“Chemicals Agents Directive”, CAD). In many cases, measured exposure data
(e.g. the concentration of a chemical in the workplace air) may be available. These can be
used provided that they adequately represent the exposure scenario (ES) considered and
meet some quality criteria (see Chapter 1.2.1).
For substances without an occupational exposure limit, however, workplace measurements
are often not available or only exist for a specific application. When workplace measurements are missing, exposure has to be estimated. Tools available for this purpose generally
follow a step-wise (tiered) approach. The level of differentiation, and thus the input
requirements, increases from lower tier (level 1) to higher tier estimation tools. This step-wise
approach ensures that a more detailed, labour-intensive assessment is not carried out for
situations, in which negligible exposure is expected.
When estimating exposure, it is important to adequately document all entered values and to
provide references for the input data. Some of the tools discussed below allow the
generation of reports, which include all input parameters, while other tools only have limited
options of documentation and print screens may be the only option available.
Note that some of the tools for exposure estimation, such as the ECETOC TRA model,
already include a risk-based approach in that exposure estimates are compared with hazard
data.
REACH requires assessing exposure resulting from all conditions of use within an exposure
scenario, including risk management measures. The exposure estimation models described
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in subsequent sections allow to various degrees to consider the reduction of exposure due to
risk management measures. This will be discussed below in the context of each model.
1.1.3
Determinants of exposure
Certain core information, the so-called determinants of release and exposure, has already
been discussed in relation to ES development (Chapters 6, Part I, and 9.3 of Part II of the
practical guide; see also ECHA CSA 2008, Part D, Chapter 2.2). These determinants, such
as substance specific properties, conditions of use and risk management measures, are very
important in the exposure estimation. For example, the vapour pressure of a liquid substance
has a decisive impact on the concentration of that substance in air and thus on inhalation
exposure. In relation to conditions of use, a higher process temperature can increase
inhalation exposure, which however can be controlled by risk management measures, such
as local exhaust ventilation.
Specific information may be available for most of these determinants. However, Tier 1
estimations usually only require very basic information and if a Tier 1 estimate does not
identify a risk (i.e. a higher tier estimate is not required), the specific information will not be
needed.
The parameters required for Tier 1 and higher tier estimations are listed in Appendix 4.1.3
and 4.1-4. These appendices also give hints on where to get the relevant data from.
1.2
How to assess occupational exposure
In principle, an exposure can be assessed on the basis of measured data or on data
generated with one of the tools described below (modelled estimates). ECHA CSA 2008
(Chapter R.14.4.1) proposes the following hierarchy:
1.
Measured data for the actual substance
2.
Measured data for analogous/surrogate substances/activities
3.
Modelled estimates.
While it is clear from this hierarchy that modelled data are only the last option (no completely
validated exposure model currently exists), measured data are not preferable per se but
have to meet certain criteria. For example, measured data for the actual substance should be
representative of the ES, robust in terms of the sample size and reliable. Having this in mind,
many measured data will not meet one or more of these criteria and analogous/surrogate
data may also fail to qualify. If lesser quality measured data are available, these will be used
together with results from the application of the tools, i.e. modelled data, being generated in
parallel. The plausibility of the values resulting from measurements and model estimates
needs to be discussed to arrive at a final estimate.
Besides, several general principles have to be borne in mind:
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
The assessment should be transparent and clear.

The assessment should be of a conservative nature, i.e. be on the safe side, and
should be conducted for all activities and routes within the ES presenting the potential
for exposure. However, exposure resulting from accidents, deliberate misuse or malfunction should not be covered. 1 Also, extreme estimates resulting from the combination of several maximum assumptions should be avoided.

Attention should be paid to subsets or subpopulations differing in exposure intensity or
vulnerability (such as women of conceptive age and pregnant women).
These and many other general principles, such as the consideration of RMMs, mentioned in
ECHA CSA 2008 (Chapter R.14) are not necessarily applicable to all assessments. For
example, Tier 1 models are already conservative and no special attention has to be paid to
this principle.
1.2.1
Basically, there are two kinds of measurement data:

Actual measurement data for the substance;

Analogous/surrogate measurement data.
These different kinds of data are described in the following matrix. Note that the use of data
for similar substances used in similar exposure scenarios involves two extrapolation steps
and therefore requires reasonable care. The rationale for using these data must be well
explained and documented.
Actual substance
Similar substance
Actual exposure scenario
Actual measurement data
Analogous/surrogate data
Similar exposure scenario
A similar substance is defined as possessing similar physico-chemical properties relevant for
exposure (e.g. vapour pressure, dustiness). To be on the safe side, a more “critical” similar
substance has to be used for analogous/surrogate data. As an example, the use of toluene
data for a xylene exposure assessment could be appropriate, since toluene is more volatile
than xylene and thus results in a conservative exposure estimate.
1
4
Council Directive 98/24/EC “on the protection of the health and safety of workers from the risks related to
chemical agents at work” is (partly) dealing with these situations.
June 2010
A similar exposure scenario is characterised by activities with similar operational conditions
of use and risk management measures, which is likely to give a reliable estimate of the
exposure in the scenario under assessment.
Generally, measurement data for the actual substance are preferred. However, high quality
analogous/surrogate data are often better than poor quality data for the substance itself.
1.2.2
Sources of measured data
Measurement data may be available from a variety of different sources, such as:

In-house data

Databases (as far as publicly available)

Surveys, e.g. by trade or similar organisations

Publicly available data (e.g. reviews, literature data)
Appendix 4.1-1 provides examples of publicly available sources for measurement data.
Chapter 8.3 (Part I of the practical guide) describes the use of existing data (e.g. the MEGA
database) in more detail.
1.2.3
Criteria and selection of appropriate measurement data
Inhalation exposure
As already mentioned above, measurement data must meet some quality criteria in order to
be representative, robust and reliable. ECHA CSA 2008 (Chapter R.14.4.5) lists several
criteria, of which the most important ones to ensure a sufficient quality of measurement data
are:

Concentration and unit of measured values given

Large sample size

Representativeness of the data for the ES under assessment (in particular, operational
conditions of use and risk and management measures)

Personal (breathing zone) sampling is preferred over static sampling.
Measurements obtained using recognised and standardised protocols for sampling and
analysis are generally preferred. If the concept of homogenous exposure groups (HEGs)
according to European standard EN 689 has been followed in the planning of the workplace
measurements this may be especially helpful to understand the representativeness of the
data (HEGs are groups of workers who experience similar exposures).
Dermal exposure
In general, there are considerably less data available for dermal exposure than for inhalation
exposure. ECHA CSA 2008 (Chapter R.14.4.5) therefore tends to use dermal data without
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applying the same strict quality criteria used for inhalation data. Again, the following list gives
some criteria necessary to ensure sufficient quality.

Concentration and unit of measured values (e.g. mass per unit area, including
conditions of the measurement such as data on surface size sampled, mass of
contaminant and duration of sampling)

Large sample size

Representativeness of the data for the ES under assessment (in particular, operational
conditions of use and risk and management measures)

It has to be clearly indicated whether data stand for exposure to a substance or
exposure to the mixture used
There are many different units of expressing dermal exposure (e.g. in mg/person, mg/cm2 of
skin or mg/cm2 x h). If the DNEL has a different unit than the exposure value, the latter may
have to be converted to the unit of the DNEL.
In addition to ECHA CSA 2008, several other documents, such as the German TRGS 401
(skin contact) and 402 (inhalation), 2 provide important information to ensure a good quality of
measurement data.
Discussion of adequacy/applicability
In order to differentiate between differences in quality of measurement data, the following
three levels are introduced:

High quality,

Intermediate quality and

Lower quality.
The types of data representing the three different levels are illustrated in the following
examples:
2
6

A measurement value (e.g. expressed as a median or 90th percentile) obtained from 26
personal sampling measurements under conditions representative of the ES under
assessment, will most probably enter the exposure estimation as a value of high
quality. Such a value might be given in branch-specific measurement reports or in an
EU Risk Assessment Report.

A mean from 3 measurements with personal sampling for the ES under assessment
(e.g. from an original literature study) is likely to be an intermediate quality value for the
exposure assessment.
Bundesanstalt für Arbeitsschutz und Arbeitsmedizin: Technical Rules for Hazardous Substances (TRGS):
Risks resulting from skin contact – determination, evaluation, measures (TRGS 401)
Ermitteln und Beurteilen der Gefährdungen bei Tätigkeiten mit Gefahrstoffen: Inhalative Exposition (TRGS
402) (available only in German). http://www.baua.de
June 2010

A value given only as a mean without the number of measurements and details on
sampling is most probably a lower quality value, especially if it is not fully representative of the activity described in the ES in question. This type of data presentation is
common in reviews (e.g. the Environmental Health Criteria series published by the
World Health Organization).
These criteria can be applied both to measurement data for the actual substance in the ES
under assessment and for analogous/surrogate data. In principle, a high quality value for the
actual substance in the ES under assessment may be used alone. An intermediate quality
value will most likely require additional analogous/surrogate measurement data or modelling
(i.e. application of estimation tools). As a general rule, it can be suggested that the lower the
quality gets, the more approaches should be taken in parallel. It may well be the case that
three approaches (e.g. lower quality measurement data for the actual substance in the ES,
intermediate quality analogous/surrogate measurement data and modelled estimates) have
to be followed and the various estimates integrated.
1.2.4
In the following sections, Tier 1 tools as proposed in ECHA CSA 2008 (Chapter R.14.4.6R.14.4.8) are explained. A brief overview and sources of Tier 1 tools are given in Appendix
4.1-2.
Users of exposure estimation tools should keep in mind that most tools are of a very
conservative nature (i.e. in most cases they tend to the cautious, higher side of exposure
estimates) and that they are only validated to a limited extend and/or for some uses.
Application of higher tier models in particular will in many situations require in depth
understanding of exposure estimation and expertise in handling the tools to avoid highly
inaccurate estimates.
ECETOC Targeted Risk Assessment (TRA)
The completely revised version of ECETOC TRA (see Appendix 4.1-2 for access and
documentation) allows the estimation of both inhalation and dermal exposure of workers.
Compared to the previous web-based version, ECETOC TRA is now implemented as a
Microsoft Excel® tool and includes many changes, which are described in more detail in the
accompanying Technical Report (see Appendix 4.1-2).
Many of the revisions implemented in the new version are aimed towards better integration
into the exposure assessment process under REACH (e.g. adoption of the PROCs).
Consequently, ECETOC TRA is now more an exposure assessment tool than a targeted risk
assessment tool (as was the previous version). However, it is still possible to calculate risk
values after entering DNELs or analogous values. Again, more details on the background of
the changes and the scope of the new version can be found in the Technical Report.
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The tool is considered to be the preferred Tier 1 model for occupational exposure estimation
(ECHA CSA 2008, Part D, Chapter 5.3).
ECETOC TRA consists of individual MS Excel® spreadsheets for the impact areas workers
and consumers. In addition, an integrated tool has been developed which covers also
environmental assessments (beside assessments of workers and consumers) (Info-Box 1)
User
guides
are
available for all these
Info-Box 1
components. The followThe integrated tool is much more complex than the individual
ing description is based
tools (using 9 different files) and follows the principles of the
on the stand-alone ECEprevious version by:
TOC TRA Worker tool.

providing a common user interface for data input and
The stand-alone ECEoutput for all three impact areas
TOC TRA Worker tool

building on a database to store data for numerous
consists of a single MS
substances with multiple use scenarios
Excel® file and an

the possibility to alter entry data stored in the database
accompanying
user
In addition, the integrated tool of the new ECETOC TRA verguide. Before starting
sion now incorporates the possibility to run a batch mode for
the tool, it is wise to
multiple substances / scenarios. This may especially be helpful
keep a copy of the
as a first screening step to gain a complete overview.
original MS Excel® file.
For more information on the integrated tool, users may consult
Depending
on
the
the Technical Report and the respective user guide.
security settings in MS
Excel®, the user may
have to enable macros upon opening the tool.
The tool starts with an example (substance “demosub1” with artificial CAS number 01-02-03)
already filled in. This may be helpful in gaining a first overview of the tool. However, before
using the tool for exposure estimation, it is useful to first select the “Clear all” button at the
end of the “InputModule” (rather than trying to overwrite the example).
There are nine tabs visible in the bottom tab bar, representing the following worksheets:

“InputModule”: this is the central data entry screen

“Fugacity”, “Value look up”, “PROC”, “Duration of Activity”, “RPE”, “Mixtures” and
“Dermal”: these worksheets contain all the values used in the calculation, e.g. exposure
reduction factors for respiratory protection, and provides a rationale for their selection
(e.g. when the new TRA exposure predictions deviate from the underlying EASE model
or from the previous TRA version); they are helpful to better understand the calculation
and also to get an idea of the influence of individual exposure determinants.

Demosub1 (01-02-03): contains the results of the exposure estimation (called “linear
report” in the tool) for the example.
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The tool provides notes on use in the “InputModule”, which basically describe the step-bystep approach (comments on each parameter are available in the fields with question
marks):

START: First enter the substance-specific data (name, CAS number, molecular weight
and data on the likelihood to become airborne). Indicative reference values (e.g. a
DNEL or some other value such as an OEL) can be entered and the tool then
calculates whether predicted exposures are higher than the reference value. However,
the user may leave these fields empty and estimate exposure only (but see limitations
below).
The “likelihood to become airborne” (fugacity) section represents a combination of
determinants, which are summarised in the following figure.
Figure 1-1:
Schematic representation of the fugacity decision tree
The decision on the dustiness of the substance involves a subjective element (see also
discussion of the EMKG-EXPO-TOOL below). The ECETOC TRA Worker tool provides some
guidance on the dustiness in the “Fugacity” worksheet (for more detailed information, see the
Technical Report (ECETOC 2004, section 2.1.1 and Appendix C as well as the addendum to
it (ECETOC 2009)) as well as Chapter R.14 of ECHA CSA (2008, draft version 2010). It must
also be stressed that for volatiles, the vapour pressure at the process temperature has to be
chosen as the basis. Therefore, ECETOC TRA may have to be run several times, if a substance is handled under similar conditions but at different temperatures.
After completion of the “input parameters” mentioned above (substance-specific data and
likelihood to become airborne) users are required to specify the conditions of use in the
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“exposure scenario builder” section of the “InputModule”. The difference between the two
sections “input parameters” and “exposure scenario builder” is important since it is possible
to retain the “input parameters” and run exposure estimations for different scenarios (see
below).
In the “exposure scenario builder”, a name should be given for the scenario, followed by
selection of the appropriate PROC and choosing either “industrial activity” or “public domain
(professional) activity” (STEP 1 in the tool). Selection of the correct PROC is not dealt with
here in detail, because this is already described in the context of ES development (Part II of
the practical guide, chapter 9.3.1). The tool automatically assigns industrial or professional
activity to some of the PROCs by disabling the alternative choice. For example, if industrial
spraying (PROC 7) is chosen, the option “public domain (professional) activity” is
automatically disabled.
STEP 2 in the “exposure scenario builder” involves application of “exposure modifiers”
(operational conditions). It is at this stage that ECETOC TRA allows user to “play around”
with the parameters and to examine the impact of these parameters on the exposure
estimation (“iteration”). For example, a liquid substance with a vapour pressure of 1000 Pa
(medium fugacity) may give the following estimates for PROC 7 (industrial spaying) at
extreme ends.
Table 1-1
Extreme estimates for a substance with medium fugacity in PROC 7
Parameter
Exposure estimate
Lowest
Highest
Outdoors
Indoors
Is Local Exhaust Ventilation present?
N/A
No
What is the Duration of the Activity?
15 minutes
>4 hours
95% reduction*
No protection
Is the substance used in a Mixture?
Yes
No
Select the concentration range (w/w)
<1%
N/A
0.0875 ppm
250 ppm
Does this activity take place indoors or outdoors?
What type of respiratory protection is used?
Result
* Respiratory protection capable offering a 95% reduction in inhaled concentrations of the substance
This example shows that exposure estimates can vary over a wide range depending on the
parameters selected. ECETOC TRA only states a default for the duration (>4 hours). For Tier
1 screening purposes, it might be a good idea to start with the most conservative parameters
(see last column in the table above). If safe use can be shown with this screening procedure,
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no further refinement is necessary. If safe use can not be demonstrated with the most
conservative parameters, users can subsequently choose less conservative parameters in a
step-by-step approach. The effect of selecting different values is detailed in the tabs for the
individual parameters. For example, changing the duration of the activity from >4 hours to 1-4
hours will reduce the estimated exposure by 40%.
When all parameters have been selected, there are two ways of presenting results:

“Generate report” will display a report on the exposure estimation in the same worksheet (“InputModule”, green box to the right of the input section). This is somewhat
confusing since this is actually the result and not an input. This report will be displayed
no matter if indicative reference values were entered or not. The result can be used in
the risk characterisation performed in a different IT environment. The “generate report”
option is particularly helpful for the iteration described above since the report is
automatically updated once parameters are altered and the button is clicked again.
Note that this report is overwritten every time the user clicks the “Generate report”
button.

“Copy scenario results to the linear report” will create a new tab (substance name and
CAS number constitute the name of this new tab), which includes the results including
a basic risk characterisation when all reference values have been entered in the
“InputModule” (but see Info-Box 2 for limitations). This functionality is especially helpful
for running different scenarios for the same substance. Each scenario is stored in the
worksheet for the substance in a new row. Use the “clear scenario” button to run an
assessment of a different scenario for the same substance. Note that this is the report
actually stored for future reference (but see discussion below).
Info-Box 2
Note that a linear report will only be properly created when reference values for both
inhalation and dermal exposure have been entered. If not, an error message will appear
but the user can nonetheless move to the linear report. This is somewhat disturbing and
the user may be uncertain whether calculations have been carried out correctly.
According to the User Guide, this issue will be solved in the next revision of the tool.
Also, remember that the automatically generated tab name for the result worksheet is
limited to 31 characters (28 characters for name and CAS number + 3 for a blank and two
brackets). Therefore, use short abbreviations or acronyms for the substance name when
starting the estimation.
In summary, the most helpful approach seems to be the iteration mentioned above, followed
by copying the results of the final iteration to the linear report and repeating the procedure for
all scenarios to be evaluated.
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As an example, exposure was estimated for a liquid with a vapour pressure of 30.000 Pa
(high fugacity). All other input parameters are included in the report produced with the
“generate report” function (Figure 1-2).
Figure 1-2
Printscreen of the result report for a liquid used in industrial spraying
This example (highly volatile liquid) has also been assessed using the EMKG-EXPO-TOOL
(chapter 1.2.4.2).
It is not always clear in the tool if a field has been disabled. For example, for a solid, the field
volatility (vapour pressure) is disabled. However, it is still possible to enter a value in the
larger cell (of which the field volatility forms part; see Figure 1-3). This does not appear to
result in erroneous calculations but may in cases be misleading for the user.
Figure 1-3
Printscreen of fields in worksheet “InputModule”
Also, once a report has been generated, the input parameters (substance-specific) cannot be
altered. The “clear all” button” has to be clicked in order to enter data for a new substance.
This is somewhat unusual but users will get used to it after a couple of data entries.
12
June 2010
More problematic in terms of content is the question of solids being used in liquid mixtures.
For example, if a solid substance is evaluated and PROC 7 (“Industrial spraying”) or PROC
10 (“Roller application or brushing”) is chosen, it is impossible to select “Yes” for the question
“Is the substance used in a Mixture?” This is not immediately plausible since some solids will
be used in liquid mixtures in these processes. In addition, ECETOC (2009) defines PROC 7
as “Spraying of the substance or mixtures containing the substance in industrial applications
e.g. coatings” (our emphasis). Users are left alone and this issue is not dealt with in the
Technical Report or the brief User Guide.
Another issue is related to local effects (e.g. skin irritation and sensitisation) following dermal
exposure. The tool has a focus on calculating a body dose (in mg/kg x d) for dermal
exposure. Within the approach of the tool this makes sense, since for the calculation of total
exposure both inhalation and dermal exposure have to be given in an identical unit.
However, a dose given in µg/cm2 skin may be more relevant for dermal risk characterisation
in some cases. A dose related to skin area is not automatically calculated in the tool, but may
be looked up in the “Dermal” worksheet. In addition, the tool does not offer the possibility to
enter a reference value in µg/cm2. Therefore, a risk characterisation on the basis of skin area
(e.g. for skin sensitisation) has to be conducted manually. The same problem does not exist
for inhalation, since concentrations are calculated in the report generated in the
“InputModule” worksheet and in the linear report.
It has to be noted that, according to ECHA CSA (2008, Chapter R.14), ECETOC TRA in
some cases substantially underestimates dermal exposure in the presence of LEV (local
exhaust ventilation) by assigning a very high efficiency to LEV for dermal exposure. ECHA
CSA (2008, Chapter R.14, draft version 2010) therefore recommends to reduce LEV
efficiency outside the tool to zero or at least a factor clearly below 90% in order to obtain a
conservative estimate.
More generally, the ECETOC TRA Worker tool is based on the EASE model and thus the
limitations of the latter apply. Basically, exposure to mists and process fumes cannot
adequately be estimated.
It is one of the very helpful features that the ECETOC TRA Worker tool allows to run several
scenarios for the same substance. These are stored as separate rows in the same
worksheet. The respective tabs are named according to substance name and CAS number
(Info-Box 2). This is very useful, if several substances are assessed within a single file, since
the resulting tabs (one for each substance) allow easy navigation between the results of the
different substances. Running more and more substances/scenarios within a single MS
Excel® file may, at a certain point, become confusing. It may thus be helpful to get an idea
about the number of substances and scenarios that require exposure estimation before
starting to work with the tool. Depending on number/scale of estimations, the user may then
decide, for example:
13
June 2010

to work with one file only (few substances with few scenarios),

to work with three files (three groups of substances with few scenarios each),

to have a separate file for each substance because many scenarios have to be
evaluated per substance or

to use the integrated version (Info-Box 1) since many substances and scenarios have
to be evaluated and the batch mode is considered helpful.
Note that the linear report (i.e. the result section actually stored and accessible after a series
of evaluations) does not contain the vapour pressure actually entered but only the fugacity
assigned to this vapour pressure. It may be helpful to manually enter the vapour pressure in
the linear report for future reference and documentation purposes.
The limitations mentioned notwithstanding, the ECETOC TRA Worker tool is very transparent
in its assumptions. It is also user-friendly due to its implementation in MS Excel®, the
possibilities of calculating different scenarios in a single file and the brief User Guide detailing
the key features.
The following example shows how ECETOC TRA may be used in the “Iterative 3-step
approach for exposure assessment” (Part II of the Practical Guide, chapter 9.8). This
approach is part of CEFICs “Guidance on Use and ES development and Supply Chain
Communication”, which is discussed in more detail in Part II of the Practical Guide, chapter
10.3).
Example:
“Iterative 3-Step approach to exposure assessment”
For substances with many uses and complicated supply chains it is laborious and sometimes
impossible for the substance manufacturer to get to know all uses. The following iterative 3step approach to exposure assessment was developed especially for companies dealing with
a large amount of substances. It offers a way to use the wide range of existing activities in the
development and shaping of exposure scenarios, integrating them in a clear-cut overall
structure and intends to make downstream communication more efficient.
Step 1: Basic exposure assessment using ECETOC TRA
In the first step, ECETOC TRA, which is considered as a conservative IT tool, is used to
make a Tier 1 exposure assessment using all process categories (PROCs) as listed in the
Guidance (ECHA CSA 2008, R.12). It is assumed that the complete list of PROCs comprises
all possible uses of the substance in question. This can be done with a minimum of
substance- and use-specific information. The following table shows the output of ECETOC
TRA for a test substance. It indicates for which of the PROCs a further assessment is
warranted to assure safe use (answer “Yes” in right column). PROCs for which this Tier 1
assessment already signals safe use receive the answer “No”.
14
June 2010
process
categories
[PROC]
Use Scenarios
PROC 1
Use in a closed process
with no likelihood of
exposure
PROC 2
PROC 3
PROC 4
Use in closed process with
occasional controlled
exposures e.g. during
sampling
Use in a closed batch
process i.e. where only
limited opportunity for
breaching arises e.g.
sampling
Duration
of activity
[hours]
> 4 hours
LEV (Y/N)
Yes
Estimated MoE
Exposition [DNEL/
est expo]
[ppm]
0,01
Further
assessment
required
31,8
No
> 4 hours
Yes
0,5
0,636
Yes
no refinement
done – if
needed, please
contact
manufacturer
> 4 hours
Yes
0,1
3,18
No
Use in a batch or other
process (including related
process stages e.g.
filtration, drying) where
opportunities for exposure
arise e.g. sampling, dis/charging of materials
> 4 hours
Yes
1
0,318
Yes
no refinement
done – if
needed, please
contact
manufacturer
Use in a batch process
including chemical reactions
and/or the formulation by
mixing, blending or calendaring of liquid and solidbased products
> 4 hours
Yes
1
0,318
Yes
for refinement
see Chapter 9.2
Spraying of the substance
or mixtures containing the
substance in industrial
applications e.g. coatings
1–4 hours
Yes
12
0,026
Yes
for refinement
see Chapter 9.2
Dis-/charging the substance
(or mixtures containing the
substance) to/from vessels
1–4 hours
No
6
0,053
Yes
for refinement
see Chapter 9.2
Filling containers with the
substance or its mixtures
(including weighing)
1–4 hours
No
6
0,053
Yes
for refinement
see Chapter 9.2
Roller application or
brushing of adhesives and
other surface coatings
1–4 hours
No
300
0,001
Yes
for refinement
see Chapter 9.2
PROC 10 Use as a blowing agent in
the manufacture of foams,
etc.
> 4 hours
Yes
0,5
0,636
Yes
no relevant
PROC
PROC 11 Use for coating/treatment of
articles, etc. (including
> 4 hours
Yes
3
0,106
Yes
for refinement
PROC 5
PROC 6
PROC 7
PROC 8
PROC 9
15
June 2010
see Chapter 9.2
cleaning) by dipping or
pouring
PROC 12 Production of products or
articles from substance by
compression, tabletting,
extrusion or pelletisation
> 4 hours
Yes
3
0,106
Yes
no refinement
done – if
needed, please
contact
manufacturer
PROC 13 Use as a laboratory reagent
1–4 hours
Yes
0,06
5,3
No
PROC 14 Use as a fuel
< 15 min
No
0,1
3,18
No
0,006
Yes
no refinement
done – if
needed, please
contact
manufacturer
PROC 15 Use as a lubricant
(including metal working
fluids)
> 4 hours
Yes
50
LEV: local exhaust ventilation; MoE: margin of exposure; DNEL: derived no effect level
Only those uses with answers “Yes” are further considered in step 2.
Step 2: Generic exposure assessment
Refinement of exposure assessment for selected uses is carried out by use of generic
exposure scenarios (GES). GES are under development in various industry sectors and
branches and it is expected that a broad range of GES will be publicly available in the future.
Only at this stage more detailed RMMs are introduced into the exposure assessment and will
lead to assurance of safe use conditions. In Step 2, various exposure estimation tools may be
used, depending on the scenario and substance properties. If available, higher tier models
can be used for consideration of exposure reduction by RMMs.
Step 3: Specific exposure assessment
If step 2 does not lead to a description of conditions and RMMs for safe use, a specific
assessment, including information from individual downstream users and refinement of
RMMs, is carried out. The exposure scenario is further developed and RMMs are proposed
for implementation, which ensure safe use of the substance for this specific use.
EMKG Exposure assessment tool
The EMKG exposure assessment tool (EMKG-EXPO-TOOL, MS Excel®) is part of the “Easyto-use workplace control scheme for hazardous substances” (EMKG: “Einfaches Maßnahmenkonzept für Gefahrstoffe”) of the German Federal Institute for Occupational Safety
and Health (BAuA). The tool uses a “banding approach” for the exposure assessment, which
is largely based on COSHH Essentials (Control of Substances Hazardous to Health
16
June 2010
Regulations), developed by the UK Health and Safety Executive (HSE). The concept of
banding means here that both input data and the result are expressed in categories (bands),
which often differ by at least one order of magnitude (see different bands in Figure 1-).
Important issues in relation to the EMKG-EXPO-TOOL are:

Requires MS Excel® 97 or later (MS Excel® 2002 not yet tested)

Estimates inhalation exposure only

Some applications and substances should not be assessed with the tool (e.g. open
spray applications, CMR substances; see worksheet “Limitations” in the tool)
The tool consists of three different worksheets, one detailing the limitations and one each for
solids and liquids. The input data required by the tool are rather basic and are listed in.
Appendix 4.1-3.
(For the occupational exposure assessment of metals and inorganic substances the MEASE
tool was developed (online available at: http://www.ebrc.de/ebrc/ebrc-mease.php), based on
the exposure estimation model EASE (see http://www.hse.gov.uk/research/rrhtm/rr136.htm)
and some measured data (see also chapter 1.2.5).).
Background information on the input parameters for the EMKG_EXPO-TOOL can be found
in ECHA CSA 2008 (Chapter R.14.4.8.1). In addition, some basic help and advice for tool
application (e.g. data entry for mixtures) is provided in fields with a question mark.
Fig. 1-4 illustrates the worksheet for liquids.
17
Figure 1-4
June 2010
Print screen of the worksheet for liquids in the EMKG-EXPO-TOOL
Application of the tool is straightforward and (with the exception of alternative input for boiling
point and operating temperature) only requires the user to click the fields highlighted in italics
and red (e.g. “Medium” in the volatility band). Tool application includes the following steps:

Define dustiness (solids) or volatility (liquids), i.e. tendency to become airborne

Indicate the scale of use band (amount of substance)
These two steps alone define the exposure potential (EP) band, which is then converted
into predicted exposure ranges in the lower right table of the worksheet (this table can be
considered the result table).

Select control strategy
This last step modifies the predicted exposure range in the respective EP column.
The output generated by the tool is in the form of ranges for the concentration of the
substance in air, given in mg/m3 for solids and in ppm (parts per million, mL/m3) for liquids.
For example, the concentration resulting for a liquid in EP 3 with LEV is 5-50 ppm (Figure 14). The upper value of the range given, i.e. 50 ppm in this example, will be used for the
comparison with the DNEL (ECHA CSA 2008, Chapter R.14.4.8.5).
18
June 2010
As already mentioned above, the EMKG-EXPO-TOOL cannot be used for some applications/substances and the user should always consult the description provided in the tool.
In addition, the estimates are generic and therefore comprise uncertainty. However, the tool
makes several conservative assumptions, such as:

The concentration of a substance (in a mixture) is assumed to be 100%.

The exposure duration is assumed to be full shift length (with the only exception of
exposures below 15 minutes).
Together with the use of the upper value of the predicted exposure range for comparison
with the DNEL, it is therefore assumed that the tool can predict safe use despite its
uncertainties.
In addition, the user should select more conservative parameters whenever uncertain about
a particular input. This is especially the case for the rating of dustiness, which contains an
element of subjectivity.
Both for solids and liquids, the exposure range predicted can become very high and will be
given as > 10 mg/m3 (solids) and > 500 ppm (liquids), respectively (EP 4 in combination with
general ventilation only). These values are close to the German OEL for total dust of 10
mg/m3 and close to the highest German OEL for vapours of 1000 ppm (both according to
TRGS 900). According to ECHA CSA 2008 (Chapter R.14.4.8.3), use of these values is not
recommended.
In general,

a higher tier assessment is required if the DNEL is below the upper exposure predicted
(e.g. DNEL = 20 ppm versus exposure predicted = 50 ppm in the example above).

safe use is shown if the DNEL is above the upper exposure predicted (e.g. DNEL =
150 ppm versus exposure predicted = 50 ppm in the example above).
ECHA CSA 2008 (Chapter R.14.4.8.5) states that safe use in the latter case is only evident
in combination with the appropriate control guidance sheet (CGS) issued by HSE
(http://www.coshh-essentials.org.uk/assets/live/g###.pdf, with ### to be replaced by the
appropriate CGS number, which in turn can be found in Appendix R.14-2 of ECHA CSA
2008; German versions with the same numbering system are available from BAuA at
http://www.baua.de/de/Themen-von-A-Z/Gefahrstoffe/EMKG/Schutzleitfaeden.html?__
nnn=true&__nnn=true). 3
3
COSHH Essentials, which is very similar to the EMKG-EXPO-TOOL is available as a web-based application
(http://www.coshh-essentials.org.uk/). The output of this tool is not as straightforward in terms of an exposure
estimate as the EMKG-EXPO-TOOL and is therefore not considered here further.
Note that there is also an “S” series of the CGS, e.g. S101 for the selection of personal protective equipment
(http://www.coshh-essentials.org.uk/assets/live/S101.pdf).
19
June 2010
These CGSs contain good practice advice on the use of the respective control measures
(e.g. on design and equipment, maintenance and personal protective equipment, if
applicable).
1.2.5
Several higher tier tools are available that can be used for exposure assessment. One of the
main problems is that they are partly still under development and any description may soon
be outdated by a new version. A brief overview and sources of higher tier tools are given in
Appendix 4.1-2.
In order to account for the specifics of metals and inorganic substances in the occupational
exposure assessment, the MEASE tool was developed (online available at:
http://www.ebrc.de/ebrc/ebrc-mease.php). It is based on the exposure estimation model
EASE (see http://www.hse.gov.uk/research/rrhtm/rr136.htm) and some measured data. It
offers a higher level of differentiation than ECETOC TRA for some parameters. For example,
the fugacity of a solid substance may not only be described in terms of low, medium or high
dustiness but also by a "massive object" category.
Stoffenmanager
The web-based Stoffenmanager tool (developed in Dutch but also available in a (limited)
English version) allows the assessment of inhalation and dermal exposure to solids and
liquids after registration on the website. While the inhalation exposure assessment results in
a quantitative estimate of the exposure concentration, dermal exposure is only addressed
qualitatively with scores ranging from 1 (negligible) to 6 (extreme).
ECHA CSA 2008 (Chapter R.14.5.1) refers to a different (spreadsheet) version, which is not
publicly available. The use of different percentiles including the 50th percentile (median), as
described in ECHA CSA 2008, however, is not possible with the public, web-based version.
Rather, the latter gives a “worst case” estimation defined as the 90th percentile.
As a higher tier tool, Stoffenmanager requires more detailed input information than e.g. the
EMKG-EXPO-TOOL discussed above. In particular, it allows to select a variety of control
measures, such as containment, different forms of ventilation and PPE (personal protective
equipment). Figure 1-5 shows an example of the type of information required by the tool. A
more extensive list of input requirements is given in appendix 4.1-4.
20
June 2010
Figure 1-5
Print screen of one of several input screens of the Stoffenmanager tool
Stoffenmanager cannot be directly used for some very specific substances/tasks (described
in more detail at https://www.stoffenmanager.nl/Public/Applicability.aspx). In addition, the
inhalation model assumes a process temperature of 20°C and thus requires expert knowledge to transform input data (vapour pressure) if the process temperature is much higher or
lower.
Stoffenmanager requires the user
to

first define some BASIC INFORMATION such as departments within the company
and suppliers of the mixtures
(called products in the tool)
and
Info-Box 3
Stoffenmanager allows importing xml files and
examples as well as some support is given on how
to use this option. However, managing the data in
xml format requires some experience and will probably only be a feasible alternative if many products
have to be evaluated with this tool.
21

June 2010
then describe the substances in a product (called components) and the products themselves (also in the basic information tab).
For only a limited number of components, it is easier to define products and then create
components with the “Create a new component” function available in the “risk
assessment” section on the product information page. For many components, it is
useful to first create all components via the “basic information – components” function.
After this basic information is entered, the RISK ASSESSMENT section serves to actually
carry out the exposure estimate for inhalation and dermal exposure. This is the main section
where detailed information on the operational conditions of use and risk management
measures is required.
The assessment results in (Figure 1-6):

a hazard class (hc): from A (low) to E (extreme), based on the R phrase assigned in
the basic information step,

an exposure class (ec): from 1 (low) to 4 (very high) and

a risk score (risk): from III (low) to I (high)
These results mirror the banding approach implemented in Stoffenmanager, which is quite
similar to the EMKG-EXPO-TOOL described above. However, Stoffenmanager also allows to
quantitatively estimate the exposure concentration in the workplace air (the “C” in the box on
the right of Figure 1-6). This exposure concentration is calculated for each component of the
product defined in the steps above.
Figure 1-6
22
Print screen of risk assessment results in the Stoffenmanager tool: inhalation
June 2010
These exposure concentrations
relate to the task selected and its
duration. If the duration is less than
shift length (8 hrs), a time-weighted
average (TWA), which is usually
required for a comparison with the
DNEL, can be derived (Info-Box
02).
Info-Box 4
Stoffenmanager allows calculating the “daily
average concentration” (i.e. TWA). It is important to
first calculate the exposure for all tasks and to
calculate the daily average concentration only after
all other steps have been finalised. For liquids, TWA
exposure to vapours of each component is calculated, while for solids (powders) TWA exposure to
the dust of the product is given. When creating a
new daily average concentration calculation, it is
important to be clear about what to calculate
(inhalable dust or vapour) as these data cannot be
altered afterwards.
The calculation of daily average concentrations is
located in the RISK ASSESSMENT tab.
Since Stoffenmanager was originally developed for priority setting
and includes hazard information on
the product (in the form of risk
phrases), exposure estimation is
only one of the functions of the tool.
For example, selection of control
measures enables the user to
identify measures, which can be used to control identified risks. In addition, an action plan
can be developed after selection of control measures that implements the actions required in
the user’s company.
The applicability of the tool has already been described above and should always be
considered in a first step.
Stoffenmanager in its current version 3.5 only allows quantitative estimation of inhalation
exposure, returning what the tool describes as a “worst case” exposure concentration
(defined as the 90th percentile). According ECHA CSA 2008 (Chapter R.14.5.1.2), typical
input values rather than extreme ones should be used when using this exposure estimate.
It also must be emphasised that the tool represents a rough approach and it is therefore not
meaningful to directly use the quantitative results that often imply a false degree of precision
(e.g. 28.64 mg/m3). Rather, it is suggested to round the result to two significant figures (e.g.
29 mg/m3).
In its current version, some functions of Stoffenmanager (among others, the very useful
reporting function and a REACH function) are limited to the Dutch language version. While
these functions will be probably available in English in future version, this currently somewhat
limits the applicability of the tool.
23
June 2010
RISKOFDERM calculator
The RISKOFDERM calculator
Info-Box 5
has been developed in the
The six processes of the tool are based on the so-called
framework of an EU research
4
Dermal Exposure Operations (DEO) units, which are
project. It evaluates dermal
described in detail by Warren et al. (2006). Table 1exposure to a mixture with a
summarises the DEO units, provides some examples
differentiation of exposure of the
for typical tasks covered by each unit and lists the main
hands and exposure of other
forms of dermal exposure. Note that the titles of the proparts of the body (hands only in
cesses are slightly different in the “Process” worksheet
DEO unit 1 and body only in
of the most recent version of the RISKOFDERM calcuDEO unit 6; see Info-Box 5 and
lator (v. 2.1) but the full titles appear in the worksheets
Table 1-2). Exposure to the
for specific processes.
constituents of the mixture has
to be calculated by multiplying the exposure to the product with the fraction of the constituent
in the product.
Besides the spreadsheet (MS Excel®) version, ECHA CSA 2008 (Chapter R.14.5.2) refers to
a web-based version of the RISKOFDERM calculator, which is currently not publicly
available, and will not be discussed here.
The spreadsheet version contains separate worksheets with only the active ones appearing
in the tab bar:

The “Start” worksheet shows up when running the tool and allows users to move on to
the “Process” worksheet (with the “Start” worksheet disappearing from the tab bar).

The “Process” worksheet is the general entry screen from which to select the process
most adequate for the ES under assessment. Again, this worksheet is no longer visible
in the tab bar once a process is selected but can always be loaded by selecting the
“Back” button in a specific process worksheet.

The “Changes and validity” worksheet includes the validity ranges of the model but
these are also included in the worksheets for the specific processes (see Figure 1-7
below).

The brief “Explanation” worksheet is important and should be consulted before using
the tool. It is also very useful to consult the RISKOFDERM calculator guidance document (see Appendix 4.1-2) as it provides details and examples on many of the processes (e.g. also activities not covered by a specific DEO unit) and also gives useful
background information on all input parameters and output values.
4
24
RISKOFDERM: "Risk assessment for occupational dermal exposure to chemicals" (2000-2004, RTD Project:
QLK4-CT-1999-01107), funded by the European Community and several national authorities and carried out
by 15 partners from 11 different Member States.
June 2010
Table 1-2
Processes of the RISKOFDERM calculator (from Warren et al. 2006 with adaptations from the
spreadsheet version)
DEO
unit
Title
Examples
Main forms of dermal exposure
1
Handling of (potentially)
contaminated objects
Mixing, filling
Contact with contaminated surfaces; also
deposition of aerosols and direct contact
or immersion
2
Manual dispersion of
products
Wiping, generally:
dispersion by a tool without
a handle
Immersion and some contact with contaminated surfaces
3
Dispersion of products
with a hand-held tool
Brushing, dispersion with a
roller or comb
Contact with contaminated surfaces and
some direct contact, e.g. splashes, drops
4
Spray dispersion of a
product
Spraying with equipment
(with or without pressure)
Deposition of aerosols and contact with
contaminated surfaces
5
Immersion of objects
into a product
Mechanical immersion
(using e.g. hoists but also
manually)
Immersion and contact with contaminated
surfaces
6
Mechanical treatment of
solid objects
Grinding, sawing
Deposition of aerosols and contact with
contaminated surfaces
The input requirements vary with the process chosen but the data needed are mostly
qualitative in nature. Appendix 4.1-4 lists the input requirements for one process as an
example.
It is useful to give the assessment a name in the “Process” worksheet to allow differentiation
between different assessments. This name is automatically transferred to the worksheet of
the process subsequently selected and the output worksheet (see below).
Once in the worksheet of the specific process, application of the tool is straightforward.
Examples and some guidance is provided in the form of comments to the individual fields
and the “Explanation“ worksheet. Users generally select the appropriate answer from dropdown lists and the results are automatically updated. This allows the user to immediately
assess the influence of the different parameters and their values.
A calculation (an example for DEO unit 3, this could be “painting a wall with a brush”) is
presented in Figure 1-7. Values were chosen to demonstrate the warning messages of the
tool, so this example is not really typical.
25
Figure 1-7
June 2010
Print screen of a DEO unit 3 calculation with the RISKOFDERM calculator (note the warning
messages and comments)
As shown in Figure 1-7, the RISKOFDERM calculator first gives the resulting exposure rate
(in µL/min) and then calculates the loading per shift (in µL) by multiplication with the
cumulative duration during a shift. The tool presents the results as a median (50th percentile)
and allows the user to set a percentile (75th percentile in Figure 1-7 but any value can be
entered in this field). If the calculation leads to unreasonably high loadings per shift, a
warning message in red appears at the bottom of the worksheet (see the various warnings in
Figure 1-7). Also, the tool warns the user if a “unrealistic” combination of application rate and
duration is used. In the example in Figure 1-7, a high application rate is combined with a long
duration, which leads to a warning message in orange. Note that both input values for these
parameters are within the validity range of the model (given in blue at the right side of the
worksheet), it is only the combination that is not covered by the model.
26
June 2010
Clicking on the red “Overview results” button opens a new worksheet with a new name (e.g.
“Dispersion results” for a DEO unit 3 calculation), which summarises the input parameters
and gives a table with preset percentiles for the results including warning messages for
unrealistic estimates where appropriate. The distribution is also graphically presented in a
standard diagram. The user may move back to the respective process worksheet still visible
in the tab bar. If input parameters are altered, values are automatically recalculated in the
“Overview results” worksheet. As a final step, the “Overview results” worksheet can be
printed using the “Print” button. However, it is more convenient to use the print function from
the file menu and its preview functionality in order to adjust the page layout.
In principle, calculations for other DEO units follow the same pattern and only require
different input parameters.
It must be emphasised that the tool estimates dermal exposure to a mixture and that
exposure to individual substances must be calculated separately. However, this step can be
integrated in the MS EXCEL® file by creating a new worksheet in which the respective results
are multiplied with the fraction of the compound in the mixture (since all cells are protected in
the tool, this requires some experience in MS EXCEL® application).
The protection of the cells also leads to other problems. First, the specific worksheet returns
results with 3 significant figures (e.g. 0.363 µL/min for a median and 23400 µL/min for an
upper percentile). The corresponding “Overview results” worksheet formats these results as
natural numbers (0 and 23374 µL/min in this example), which is not considered meaningful
but cannot be altered by the user. Second, worksheets cannot be copied to the clipboard and
used in other software such as MS WORD®. Again, there is a workaround by creating a new
worksheet and integrating the results but this again requires some knowledge in MS EXCEL®
application.
Furthermore, the RISKOFDERM calculator (even though a higher tier tool) does not take
account of PPE and only estimates potential dermal exposure (Chapter 1.1.1 above). The
effect of PPE in reducing exposure must therefore be evaluated separately. Since exposure
both of the hands and the body is calculated in most DEO units, the differential effect of PPE
can be assessed. For example, it might be sufficient to envisage protective gloves only if
exposure of the hands is much higher than exposure of the body.
The tool does not allow combining estimates for separate tasks (e.g. mixing (DEO unit 1) and
brush application (DEO unit 3)) to full shift estimates. Adding up the different exposure
estimates would not take account of removal of contamination between tasks (e.g. by
washing hands or incidentally) and might also lead to an overestimation when combining 90th
percentiles.
27
June 2010
Other tools
There are several other tools, which may be used for specific purposes. For example, the
software SprayExpo, originally developed to assess exposure to biocidal products during
spray application, can be a useful tool for these types of applications. The tool can be
downloaded (together with a manual and background information) from the website of the
German Federal Institute for Occupational Safety and Health 5 .
1.2.6
Efficiency of risk management measures (RMMs)
The exposure estimation models discussed above at best only consider some types of risk
management measures (RMMs). Therefore, results obtained from exposure estimations may
have to be modified to include the efficiency of RMMs described in the exposure scenario. (In
practice it is decisive that the measures are implemented with high effectivity!).
Information on efficiency of RMMs are available from various sources, but no comprehensive
compilation of information exists yet. The “Library on Risk Management Measures (RMM
Library)” as developed in REACH Implementation Project 3.2
(http://www.cefic.be/Templates/shwStory.asp?NID=494&HID=645) contains some information on the efficiency of individual RMMs, but needs further development. In the RMM Library
typically two efficiency values are given: a “typical default value” (estimate of the 50th
percentile) and a “maximum achievable value” (applying best practice). More information on
how to work with the RMM library is given in ECHA CSA 2008 (Part D, Chapter 4.6.2).
Information on efficiency of inhalation protection measures is also available, for example, in

BGR 190 (BG Regel 190, Rule 190 of the German Berufsgenossenschaften
(Employer's Liability Insurance Associations), BGFE 2004); in this document, efficiency
of inhalation protection equipment is generally expressed as the factor, by which the
exposure concentration is allowed to exceed the occupational concentration limit, when
wearing the equipment,

the new “Technical Notes for Guidance” for “Human Exposure to Biocidal Products”
(EC 2008) also contain the factors from BGR 190, together with British and American
standards,

Marquart et al. (2008) listed in their publication the inhalation protection factors used in
the tool “Stoffenmanager”,

Fransman et al. (2008) describe systematic efforts of data collection on the efficiency of
RMM and of building an „Exposure Control Efficacy Library (ECEL)“.
5
28
http://www.baua.de/nn_7554/en/Publications/Expert-Papers/Gd35.html?__nnn=true
June 2010
For estimating the reduction of systemic exposure from dermal contact at the workplace by
suitable personal protection equipment a default factor of 90% is often used (TNO 2007).
Default values for dermal protection measures are also contained in the “Technical Notes for
Guidance” for “Human Exposure to Biocidal Products”, which provides factors expressing
percentage of reduction of exposure (EC 2008). (For toxic endpoints as irritation/corrosion or
sensitisation a qualitative risk characterisation has to be carried out, see the following
chapter.)
1.3
As explained in chapter 3.1, Part I of the practical guide, in the risk characterisation part of
the chemical safety assessment information on exposure is compared with the hazard data
for a specific substance. In this step, exposure estimates are compared with the dose levels
without (or with low) concern (i.e. DNELs, derived no effect levels, or DMELs, derived minimal effect levels, for substances without threshold). This process, relying heavily on expert
judgement and experience, is described here only in general terms. For a more detailed
description of approaches the reader is referred to ECHA CSA 2008 (Part E).
Risks for humans are considered to be adequately controlled if
the RCR (risk characterisation ratio) = exposure level / DNEL < 1,
i.e. the DNEL exceeds the exposure level.
In the case of substances with non-threshold effects, for which a DMEL has been derived,
exposure levels below the DMEL characterise a low, tolerable risk. DNELs/DMELs should be
derived for all critical endpoints and pathways.
When exposure to a substance in a specific setting occurs via several exposure routes,
these combined exposures should be considered. This can be done either by summing up
exposure doses and comparing the total exposure with an adequate DNEL or by adding up
RCRs calculated for individual pathways.
In some cases, there may be information on toxic effects for some toxicological endpoints,
but no data to allow derivation of a DNEL or DMEL. ECHA CSA 2008 (Part E, Chapter 3.4.1)
in this regard mentions acute toxicity, irritation/corrosion (skin and eyes), sensitisation,
mutagenicity and carcinogenicity. In this case, a qualitative risk characterisation has to be
carried out with the aim of showing adequate control of risks. Guidance on how to carry out
such an assessment can be found in ECHA CSA 2008 (Part E).
1.4
Communication of the results in exposure scenarios
The risk characterisation leads to a description of the use conditions (operational conditions
of use and risk management measures), under which safe use of the substance can be
shown. These use conditions form the essential part of the exposure scenario, which has to
be communicated down the supply chain.
29
June 2010
The information of the ES has to be used by the downstream user (DU) to check whether his
substance use is within the conditions of use considered by the registrant (“compliance
check”). The registrant can provide the DU with scaling methods as a part of the ES. Scaling
methods are simple equations by which the DU can demonstrate that he operates within the
conditions of the ES even if (some of) his conditions of use differ from those described by the
registrant. Scaling and related tools are described in Part I of the practical guide, chapter 7.7.
Please note: application of scaling is only possible if the registrant provides the respective
equations and a transparent description of his exposure estimation.
Linear correlations are the most easily applicable scaling rules. Examples for determinants
linearly related to exposure can be (but may depend on the ES and the exposure model
used):

Amount used

Concentration in mixture used

Efficiency of different forms of local exhaust ventilation (in percent).
Scaling of non-linearly correlated determinants generally require application of more
complicated exposure models or other tools, which should be clearly described and provided
by the registrant, when proposing such scaling rules.
As a scaling rule the registrant may also explain how the exposure concentration has been
estimated and give the model/algorithm used for the estimation. In this case the DU is able to
use the same algorithm, but modify the input parameters and check, whether under his
conditions the estimate is still below the DNEL given by the registrant..
1.5
References
BGFE, Berufsgenossenschaft der Feinmechanik und Elektrotechnik; BGR 190: Berufsgenossenschaftliche Regeln für Sicherheit und Gesundheit am Arbeitsplatz: Benutzung von
Atemschutzgeräten, April 2004
(http://www.bgbau-medien.de/site/asp/dms.asp?url=/ZH/z701/titel.htm)
EC, European Commission; Human Exposure to Biocidal Products. Technical Notes for Guidance;
European Chemicals Bureau, endorsed at the 25th meeting of representatives of
Members States Competent Authorities for the implementation of Directive 98/8/EC
concerning the placing of biocidal products on the market (19-21 June 2007);
January 2008
ECETOC, European Centre for Ecotoxicology and Toxicology of Chemicals: Technical Report No. 93.
Targeted Risk Assessment. Brussels, Belgium, 2004 (http://www.ecetoc.org)
Fransman, W., Schinkel, J., Meijster, T., van Hemmen, J., Tielemans, E., Goede, H.; Development
and evaluation of an Exposure Control Efficacy Library (ECEL); Annals of
Occupational Hygiene, Vol. 52, 2008, 567-575
30
June 2010
Marquart, H., Warren, N. D., Laitinen, J., van Hemmen, J. J.; Default values for assessment of
potential dermal exposure of the hands to industrial chemicals in scope of
regulatory risk assessments; Annals of Occupational Hygiene, Vol. 50, 2006, 469489 (free full text: http://annhyg.oxfordjournals.org/cgi/reprint/50/5/469)
Marquart. H., Heussen, H., Le Feber, M., Noy, D., Tielemans, E., Schinkel, J., West, J., van der
Schaaf, D.; ‘Stoffenmanager’, a Web-Based Control Banding Tool Using an
Exposure Process Model; Annals of Occupational Hygiene, Vol. 52, 2008, 429-441
Packroff, R., Johnen, A., Guhe, C., Görner, B., Lotz, G., Tischer, M., Kahl, A.; Easy-to-use workplace
control scheme for hazardous substances. Project group “Easy-to-use workplace
control scheme for hazardous substances” of the German Federal Institute for
Occupational Safety and Health; Dortmund 2006
(http://www.baua.de/nn_18306/en/Topics-from-A-to-Z/HazardousSubstances/workplace-control-scheme.pdf)
Tielemans, E., Noy, D., Schinkel, J., Heussen, H., van der Schaaf, D., West, J., Fransman, W.;
Stoffenmanager Exposure Model: Development of a Quantitative Algorithm; Annals
of Occupational Hygiene, Vol. 52, 2008, 443-454
TNO Quality of Life; TNO report V7333: Effective Personal Protective Equipment (PPE), Default
setting of PPE for registration purposes of agrochemical and biocidal pesticides,
Gerritsen-Ebben et al.; Zeist 2007
(http://www.bozpinfo.cz/priloha/euroshnet_02.pdf)
Warren, N. D., Marquart, H., Christopher, Y., Laitinen, J., van Hemmen, J. J.; Task-based dermal
exposure models for regulatory risk assessment; Annals of Occupational Hygiene,
Vol. 50, 2006, 491-503 (free full text:
http://annhyg.oxfordjournals.org/cgi/reprint/50/5/491)
31
2
2.1
June 2010
Consumer exposure estimation
Aim, basic concepts and main determinants of consumer exposure assessment
and risk characterisation
This section describes the step-wise (tiered) approach for the estimation of consumer
exposure to substances themselves, substances in mixtures (e.g. solvents in glues) or
substances in articles (e.g. textile dyes in clothes). For the special case of articles, it is also
worth consulting the “Guidance on requirements for substances in articles” (ECHA Articles
2008).
ECHA CSA 2008 (Chapter R.15.1.1) defines all mixtures and articles for which consumer
exposure estimation is feasible as “consumer products” or simply products.
The general public may be exposed to substances in several ways, for example:

to substances used by consumers;

to substances in mixtures used by consumers;

to substances in articles used by consumers;

to substances at home used by professionals;

to substances in indoor air (private and public) released from building materials;

to substances in public areas;

indirectly via the environment.
Some of the basic ideas (e.g. on routes of exposure) and main determinants have already
been described in relation to occupational exposure. However, consumer exposure estimation differs in several important respects from occupational exposure. The following list describes some issues to keep in mind when assessing consumer exposure:

Certain subpopulations (e.g. children) might specifically need to be addressed in
consumer exposure estimation, as they might differ in the type and level of exposure
and in their vulnerability from the average.

Oral exposure is sometimes an important route in consumer exposure estimation, but
generally not for occupational exposure.

Adequate measured data are less often available for consumer exposure. But some
data, e.g. from indoor air monitoring programmes, may serve as additional information
to check the plausibility of model estimates. For example, when inhalation exposure
from a volatile chemical in articles is estimated and such an article is present in many
homes, then model estimates by far exceeding concentrations measured in indoor air
should be checked for plausibility.

Consumer exposure is sometimes less frequent so that short-term (acute) exposure
estimates for a single event may be more meaningful (and should possibly be
32
June 2010
addressed in the risk characterisation) than long-term (chronic) exposure levels.
Sometimes, a consumer product may lead to an acute (peak) exposure during
application and to a chronic exposure due to residues of the product (e.g. a carpet
shampoo). Both exposures have to be assessed separately and high peak exposures
(e.g. for 10 minutes) should not be averaged (over the whole day).

Consumer exposure estimation should consider normal uses and reasonably
foreseeable misuses (e.g. over-dosing a dishwasher detergent, chewing of a pen) but
not deliberate abuse or accidental situations (e.g. swallowing of the dishwasher
detergent).

Annex I of REACH (“General provisions for assessing substances and preparing
chemical safety reports”) instructs the registrant to assume that risk management
measures described in the exposure scenarios have been implemented. This includes
instructions and recommendations for use of personal protection equipment by
consumers. In the view of the Competent Authorities, mainly product-integrated RMMs,
but not those communicated to consumers (e.g. recommendations for personal
protection equipment) should be considered in the exposure estimation, as for the latter
compliance cannot be assured for a high percentile of the consumers (de Bruin et al.
2007). ECHA CSA (Chapter R.15.3) also points out that “effective risk management
measures for consumers are usually product-integrated measures (e.g. concentration
limits, package size).”

Substances can be emitted from articles by a variety of mechanisms, e.g. by evaporation, by leaching into saliva or sweat, by diffusion into skin or due to wear and tear
(see Info-Box 5).

Some of these characteristics may combine, e.g. “mouthing” of articles (toys) by a
subpopulation (small children) leading to oral exposure, which does not have to be
considered for other populations.
33
June 2010
Info-Box 5
The following questions, taken from the ECHA CSA 2008, may help to identify exposure
pathways from articles.

Can the article be put in the mouth unintentionally (e.g. chewing) or is it intended
to be?

Is there skin contact with the article, e.g. textiles, belts, shoes etc.?

Can the article or parts or particles of it be ingested?

Can substances in the article evaporate and thus be inhaled (based on default or
measured release rates)?

Can the article release the substance, e.g. due to abrasion, sawing, handling or
heating and thus lead to exposure via dust or fumes?
Eye contact with substances in articles is generally not considered a relevant pathway but
may have to be addressed if eye irritants are to be intentionally released from the article.
2.2
2.2.1
How to estimate consumer exposure
In ECHA CSA 2008 (Chapter R 15.4), basic equations for consumer exposure estimation are
given, which can be considered a Tier 0 approach to be used for spreadsheet calculations.
Generally, the same exposure equations and models can be used to estimate consumer
exposure to substances from articles (ECHA CSA 2008, Chapter R.17) or consumer
exposure to pure substances or substances from mixtures (Chapter R.15). Release of
substances from articles will often be reduced, e.g. due to influences of a solid matrix. But
this is generally not considered in a Tier 0 approach (see the following Chapter 2.2.4).
Tier 0 exposure estimation basically represents a very rough screening with worst-case
assumptions (instantaneous release of the substance without any removal). If safe use can
be shown under these conditions, no higher tier assessment is necessary. Currently, no
models for consumer exposure estimation exist that can be considered as completely
validated.
Input parameters for the following equations are generally specific for the ES under
examination. This is for example the case for the amount of product used and the weight
fraction of a substance in a mixture. However, default values are available for body weight
and skin surface area. In addition, ECHA CSA 2008 (Appendix R.15-4) provides some
values for room volumes. These data are given in Appendix 4.2-1.
34
June 2010
Inhalation exposure
A very simple, worst case equation for Tier 0 screening purposes assumes that

the substance in a product is completely released instantaneously (without consideration of substance-specific physico-chemical properties) and that

there is no ventilation.
The equation can be applied to substances released from a product (i.e. a mixture or an
article) as a gas or particulate and gives the concentration of the substance in air.
Cinh
=
with
Cinh
Qprod
Fcprod
Vroom
Qprod x Fcprod
Vroom
Concentration of the substance in the room [mg/m3]
Amount of the product used [kg]
Weight fraction of the substance in the product [mg/kgprod]
Room volume [m3]
Note:
Units of parameters in this and the following equations deviate from those used in ECHA CSA 2008 (Chapter
R.15.4.1.1) to obtain more common units for the results (e.g. mg/m3 instead of kg/m3 for inhalation exposure)
The following example demonstrates application of the above equation.
Example:
The scenario is brushing an object with 500 mL of a paint that contains 20% (w/w) of the
volatile substance X. In this case (liquid mixture), the density of the paint has to be taken into
account, which is 1.43 g/mL according to the SDS. The amount of paint used (Qprod) is
therefore (500 mL x 1.43 g/mL =) 0.715 kg. The weight fraction of substance X in the paint is
(20 g /100 g =) 200 000 mg/kgprod.
Application will be carried out in a hobby room. While Appendix 4.2-2 (and Appendix R. 15-4
in ECHA CSA 2008) do not contain a specific value for this room type, the value of 16 m3
(sleeping room) appears to be reasonable (5.3 m2 with a height of 3 m).
Exposure to substance X can thus be estimated as:
Cinh
=
Cinh
=
Qprod x Fcprod
Vroom
0.715 kg x 200 000 mg/kg
16 m3
35
Cinh
June 2010
8938 mg/m3
=
This value will be rounded to 8900 mg/m3.
The product-specific input parameters Qprod and Fcprod will be available
to the assessor and room volumes
can be taken from Appendix 4.2-2 if
the ES refers to application in a particular setting (e.g. in a kitchen or
bathroom).
Info-Box 6
If the inhalable or respirable fraction is know, it
should be taken into account. The Guidance (ECHA
CSA 2008, Chapter R.15) provides an equation
(Equation 15-2) to calculate the body dose resulting
from inhalation of the respirable fraction and gives
advice how to calculate the oral exposure resulting
from swallowing the non-respirable fraction as well
on how to estimate the overall systemic exposure
from inhalation and oral exposure.
In some cases (e.g. when acute
respiratory effects are of concern),
the type of exposure is better represented by a short-term peak exposure (for a few minutes) in the immediate vicinity of the user. In this case, the room volume can be reduced to e.g. 1 or 2 m3.
The calculated concentration of the substance is compared to the long-term DNEL in the
standard case and to the short-term DNEL in the latter case (peak exposure).
Dermal exposure
The Tier 0 dermal exposure estimation differentiates two distinct scenarios:

Dermal scenario A: instant application of a substance contained in a mixture.

Dermal scenario B: a non-volatile substance migrating from an article.
It is important to realise that dermal exposure estimation can lead to a dermal load (expressed in mg/cm2 skin) relevant for local effects (e.g. irritation) or a dermal dose (expressed
in mg/kg body weight and day) relevant for systemic effects. Both are calculated as external
exposure values, i.e. percutaneous absorption – although important for an evaluation of
systemic effects – is not considered in this step.
As already described for occupational exposure, some substances predominantly exert local
effects such as skin or eye irritation and corrosion and skin sensitisation. In these cases, it
may be difficult to quantify these effects and to derive DNELs. Dermal exposure estimation
may then not be meaningful and a qualitative risk characterisation should be carried out to
identify suitable risk management measures.
36
June 2010
Dermal scenario A: instant application of a substance contained in a mixture
The equation used for this scenario is very similar to the one for inhalation exposure (see
above). This calculation assumes that all of the substance in the mixture is applied to the
skin, which clearly represents a worst case assumption.
Lder
=
Qprod x Fcprod
Askin
with
Dermal load: amount of substance on skin area per event [mg/cm2]
Amount of the product used [mg]
Weight fraction of the substance in the product [-]
Surface area of the exposed skin [cm2]
Lder
Qprod
Fcprod
Askin
Again, the product-specific input parameters will be available to the assessor. The skin
surface area exposed requires:

a judgement on the body parts exposed: this should be evident from the type of mixture
in many cases (e.g. fingertips when using tube glue).

data for the surface area of these body parts: see Appendix 4.2-1.
Application of the above equation is illustrated by the following example.
Example:
The scenario is use of a glue marketed in a tube. Exposure to an additive Z contained in the
glue at a concentration of 0.5% (w/w; Fcprod = 0.005) has to be assessed. The amount of
product (Qprod) used should be available from the ES. If specific values are unavailable, the
respective ConsExpo fact sheets may provide relevant data. For this example, the ConsExpo
fact sheet for do-it-yourself products (ter Berg et al. 2007) assumes a value of 0.08 g (80 mg)
for tube glue and this value is used here.
It is further assumed that exposure occurs only to the fingertips. The skin surface area of the
fingertips (Askin) is not included in Appendix 4.2-1, and Appendix R. 15-4 (“Data references”)
of ECHA CSA 2008 also contains no data. Again, the ConsExpo fact sheet is a useful source
and the value of 2 cm2 reported by ter Berg et al. (2007) for fingertips in the tube glue
scenario is used.
Lder
=
Qprod x Fcprod
Askin
37
Lder
=
Lder
=
June 2010
80 mg x 0.005
2 cm2
0.2 mg/cm2
For other scenarios the dermal load per day (and not per event) may be required. For
example, Api et al. (2008) recently proposed a quantitative risk characterisation framework
for skin sensitizers, in which consumer exposure levels are expressed as mass per cm2 of
skin per day. These daily dermal loads can easily be obtained from the equation above by
multiplication with the number of events per day if there is more than one event per day.
If systemic effects need to be considered, the dermal dose has to be calculated according to
the following equation:
Dder =
Qprod x Fcprod x n
BW
with
Dder
Qprod
Fcprod
n
BW
Dermal dose: amount of substance potentially taken up [mg/kg body weight and day]
Mean number of events per day [1/d]
Body weight [kg]
Example:
The above example is extended to calculate the dermal dose. The body weight (BW) is taken
from Appendix-Chapter 4.2.1 (65 kg). The only other parameter missing is the mean number
of events (n). This may be available from the ES. An alternative source are the ConsExpo
fact sheets with the one for do-it-yourself products (ter Berg et al. 2007) giving 1 event/week
(0.14 events per day) for the use of tube glue (the result is the daily dose averaged over
1 week).
Dder =
Dder =
38
Qprod x Fcprod x n
BW
80 mg x 0.005 x 0.14/d
65 kg
June 2010
Dder
=
0.0009 mg/kg x d
The mean number of events
per day will be available from
the specific ES under examination but can sometimes also
be derived from other sources
(see example in the box 7
above).
Info-Box 7
ECHA CSA 2008 (Chapter R.15.4.1.2) contains instructions on how to calculate exposure if the substance is contained in a liquid mixture that is further
diluted. The respective equations can also be used for
some other specific cases, e.g. a non-volatile substance in a volatile medium.
Dermal scenario B: a non-volatile substance migrating from an article
The fundamental difference between this scenario and dermal scenario A discussed above is
that articles are considered here and, as such, not all of the substance will be in contact with
the skin. The main task then is to estimate the amount of substance that will migrate from an
article (e.g. textiles) in contact with the skin during 24 hours (default for Tier 0 screening).
Compared to the scenarios discussed so far, the calculations are more complex and require
more parameters.
Dermal load for this scenario is calculated with the following equation:
Lder
=
Qprod x Fcprod x Fcmigr x Fcontact x Tcontact
Askin
with
Lder
Qprod
Fcprod
Fcmigr
Fcontact
Tcontact
Askin
Migration rate: Fraction of substance migrating to skin per hour [mg/mg and hour]
Fraction of contact area for skin: article is only in partial contact with skin [m2/m2]
Contact duration [hours]
As a default, Fcontact is set to 1 (ECHA CSA 2008, Chapter R.15.4.1.2) and will not considered
here further. Of the two other parameters not previously addressed (Fcmigr and Tcontact),
information on the contact duration Tcontact may be available from the ES. The migration rate
Fcmigr depends on a variety of factors (e.g. the matrix of the article). A worst-case estimate
should be derived for Fcmigr based on known properties of the article and used in the
assessment. Alternatively, higher tier models may be used.
39
June 2010
The following example illustrates application of the above equation by using a model
calculation carried out by BfR (2007).
Example:
The scenario considered is exposure to a textile dye contained in a textile at a concentration
of 10 g/kg. All input values were taken from BfR (2007).
Qprod and Fcprod are not separately available but are calculated as follows: the textile mass
(100 g/m2) and the skin area (1 m2) result in 100 g of textile, which contain 10 g/kg of the
dye, i.e. 1 g of dye in the textile. Please note that the term Qprod x Fcprod is useful in many
cases to calculate the amount of substance contained in an article but that this term can be
substituted if the amount of substance is known or can be calculated by other means as in
this example.
The migration rate is given as 0.5% for the contact duration (Tcontact) of 16 hours (0.5 mg/100
mg x 16 h). Fcontact is set to 1 (see above).
Lder
=
Lder
=
Lder
=
Qprod x Fcprod x Fcmigr x Fcontact x Tcontact
Askin
1000 mg x 0.5 mg x Fcontact x 16 h
100 mg x 16 h x 1 m2
5 mg
m2
The result can be converted to:
Lder
40
=
0.5 µg/cm2
June 2010
The dermal dose is calculated from the dermal load:
Lder x Askin x n
Dder =
BW
with
Dder
Lder
Askin
n
BW
Dermal dose: amount of substance that can potentially be taken up [mg/kg body
weight and day]
Body weight [kg]
For both dermal scenarios it is important to realise that the dermal load (in mg/cm2 skin) is
calculated for one event and will generally be compared with the acute DNEL for local effects
expressed in the same unit (see ECHA CSA 2008, Chapter R.8.1).
The dermal dose will usually be compared with the long-term DNEL for systemic effects
since an acute DNEL for systemic effects is typically not derived for the dermal route (see
ECHA CSA 2008, Chapter R.8.1).
Oral exposure
ECHA CSA 2008 (Chapter R.15.4.1.3) presents only one scenario for oral exposure.
Oral scenario A: unintentional swallowing of a substance in a product during normal use
At the very basic level, the oral intake is calculated with the equation:
Doral =
Qprod x Fcprod x n
BW
with
Doral
Qprod
Fcprod
n
BW
Intake of the substance [mg/kg body weight and day]
Body weight [kg]
This equation is intended to be used both for mixtures and articles or, more realistically, parts
of articles. Typical examples are the swallowing of (parts of) articles by small children (e.g.
parts breaking away from a toy car) and scraped off product material due to chewing on a
pen by older children and adults.
41
June 2010
Example:
The scenario is the unintentional swallowing of modelling clay by a child and the resulting
exposure to substance A contained in the clay at a concentration of 1% (Fcprod = 0.01). ECHA
CSA 2008 (Appendix R. 15-4) does not give body weight data for children. Again, the
respective ConsExpo fact sheet (Bremmer and van Veen 2002) provides important data for
input parameters. The age of the children playing with modelling clay is assumed to be
4.5 years by default and the respective body weight (BW) is 16.3 kg. The mean number of
events (n) for playing with modelling clay is 52/year (0.14/d) and this figure is used here,
assuming the worst-case that modelling clay is swallowed each time the child plays with it.
The product amount ingested (Qprod) is given as 1 g (1000 mg, derived from product volume
and density), although this is a poorly documented estimate (Bremmer and van Veen 2002).
Doral =
Doral =
Doral
=
Qprod x Fcprod x n
BW
1000 mg x 0.01 x 0.14/d
16.3 kg
0.086 mg/kg x d
Info-Box 8
Besides the swallowing scenario, some articles might be put into the mouth without actually
being swallowed (mouthing). In this case, a substance may migrate into saliva and subsequently be ingested. ECHA CSA 2008 (Chapter R.17) proposes to use the equation
above for screening purposes (the equation above assumes complete release of the
substance) or to use data provided by van Engelen et al. (2006) specifically for the mouthing
behaviour of children. Bremmer and van Veen (2002) also give useful values for several
parameters both for the direct swallowing and the migration scenario.
ECHA CSA 2008 provides another equation that can be used if the substance is diluted
before swallowing takes place. In addition, the equation may also be used if oral intake of the
non-respirable fraction of inhaled particles has to be considered (see section “inhalation
exposure” above).
42
June 2010
In most cases, the exposure estimation for oral intake will be compared with the long-term
DNEL for systemic effects since an acute DNEL for systemic effects is usually not derived for
the oral route (see ECHA CSA 2008, Chapter R.8.1).
Please note that the scenarios and formulas above do not cover all possible consumer
exposure situations. For example, for substances accumulating in house dust, ECHA CSA
2008 (Chapter R.15.4.1.3) recommends to measure actual concentrations in house dust,
which then may be used for estimating inhalation, oral and dermal exposure. More generic
scenarios for consumer exposure can be expected to be available in the future.
Info-Box 9
If specific information is missing on some of the parameters required in the equations
above (e.g. frequency of use, room volume for specific applications, or product amount
used), it is useful to consult the defaults database of the ConsExpo 4.1 software
(described in detail below). It contains several values for these parameters (e.g. amount of
dishwashing powder used, adapted “room volumes“ modelling the immediate vicinity of
the user for some applications). Useful background information is available in the form of
“fact sheets”, which e.g. describe the origin and nature (e.g. 75th or 90th percentile) of
these values. Fact sheets are available at the website: www.consexpo.nl.
2.2.2
As already noted for occupational exposure estimation (chapter 1.2.4.1), ECETOC TRA is
now implemented as a Microsoft Excel® tool and includes many changes, which are
described in more detail in the Technical Report (ECETOC, 2009). While consumer exposure
can also be estimated with the integrated version briefly alluded to above (see Info-Box 1,
Chapter 1.2.4.1), the stand-alone version of the ECETOC TRA Consumer tool is discussed
here in more detail. Similar to the Worker tool, the Consumer tool comes as a single MS
Excel® file, a back-up copy of which should be retained before entering data.
Compared to the previous version, the ECETOC TRA Consumer tool now fully implements
the REACH product categories (PC) and article categories (AC). Many of these categories
are further divided into sub-categories with different scenarios (which may differ in target
populations, exposure routes and default input values). For example, PC31 (“Polishes and
wax blends”) has the sub-categories

„Polishes, wax / cream (floor, furniture, shoes)” and

„Polishes, spray (furniture, shoes)“.
Note that while the ECETOC TRA Worker tool uses process categories (PROCs, see
Chapter 9.3), the Consumer tool uses PCs and ACs, i.e. the product or article in which the
substance is finally used is crucial for the exposure estimation.
43
June 2010
In addition, the algorithms used in the calculations have been revised to a minor extent and
the values of parameters used in these algorithms have been changed, sometimes
substantially (see ECETOC 2009 for details). However, many basic concepts of the original
version remain in place, for example:

The tool automatically assigns the relevant exposure routes to each PC and AC

The bioavailability of a substance is assumed to be 100% for all routes of exposure

The values of default parameters are fixed except for two key parameters per route of
exposure (e.g. the amount of substance used per event for inhalation exposure)

Systemic exposure from all routes can be added for each sub-category but exposure
from different sub-categories is not added up.
Upon starting the tool and after enabling macros at the security warning, the tool opens the
first (“user input”) of eight worksheets, between which the user can navigate by using the
tabs. It is helpful to divide the eight worksheets in three groups:

Input (one worksheet)
The worksheet “User Input” contains the sections where actual user input is required
and, in fact, it is the only one where user input is allowed.

Results (five worksheets)
The worksheets “Results by Sentinel Prod” and “Results by Prod Subcat” contain the
results depending on what has been chosen in the “user input” (sentinel products/
articles, product/article sub-categories or both). These two worksheets also show the
risk characterisation results (when reference values have been entered). The worksheets “Dermal (Prod Subcat)”, “Oral (Prod Subcat)” and “Inhalation (Prod Subcat)”
contain details on the estimation per sub-category, differentiated by route of exposure
(see Info-Box 10).

Defaults (two worksheets)
The “Defaults” and “Defaults2” worksheets contain several defaults, e.g. the route of
exposure considered relevant for a particular PC or AC sub-category, and underlying
anthropometric parameters (e.g. body surface areas).
44
June 2010
Info-Box 10
The tool allows estimating exposure for a specific sub-category and/or a sentinel product
(i.e. at the PC or AC level). If sentinel product calculation is chosen, the output is for the
sub-category giving the highest exposure estimate. For example, one may choose
“sentinel product” for PC1 (“Adhesives, sealants”) and the sub-category resulting in the
highest exposure estimate is displayed in the “Results by Sentinel Prod” worksheet. If the
exposure estimated for the sentinel product demonstrates safe use (when compared with
the reference value), then safe use is also demonstrated for the respective sub-categories.
It must be stressed that the sentinel product can be different for different routes of
exposure. For example, oral exposure for PC 9 is only assessed for children for the subcategories “finger paints” (PC9c) and “modelling clay” (PC9b-3), which are therefore the
sentinel products for oral exposure. A different sub-category may be the most relevant one
for another route.
Also note that the ECETOC TRA Consumer tool differentiates between children and adults.
Generally, exposure is estimated either for adults or children for a particular sub-category
(e.g. exposure to finger paint is calculated for children only). In some sub-categories,
however, both groups are considered, but with different exposure routes. For example, oral
exposure is considered relevant for children, while dermal and inhalation exposure is
considered relevant for adults in AC 5-1 (“Clothing”; see “Defaults” worksheet of the tool for
more details).
Data input in the tool is straightforward due to the colour-coding employed. Cells requiring
user input are in green while fields that automatically calculate a value are in pink. Grey cells
can be populated with values chosen by the user, which must be documented and explained
(default values are used if these fields are left empty). However, only some parameters are
open to user input and are shown under the heading “optional” in the “user input” worksheet:

amount of product used,

fraction of the substance in the product/article and

skin contact area.
User-specific input for these parameters is only possible if the parameter is needed for
exposure estimation in the specific sub-category. For example, if only inhalation exposure is
considered relevant by the tool, the skin contact area cannot be altered in the “user input”
worksheet.
Generally, exposure estimation is carried out in the following sequence in the “user input”
worksheet (Figure 2-1):

Enter a value for the vapour pressure (the respective default fraction released to air is
automatically assigned).
45
June 2010

Enter all reference values (e.g. DNELs) in the correct units, with the inhalation
reference value given either in mg/m3 or in mg/kg x d. 6 The worst-case reference value
is generally the lowest of the reference values (but see below).

Select the relevant sentinel products and/or sub-categories (see Info Box 10) by
inserting an “x”. There is no limit as to the number of sentinel products or subcategories being evaluated at the same time.

Select if product is a spray if not already selected by default and if the respective cell is
grey (i.e. open to user input). For example, “spray” may be chosen for water-borne
latex wall paints (PC 9a-1), but not for finger paints (PC 9c). The fraction released to air
for a spray is always 1. It cannot be altered and overwrites the fraction released to air
based on the vapour pressure of the substance.

As a last step, change default values in columns F to K if applicable (see below).
Changing default values is only allowed for some of the parameters such as the
product ingredient fraction (i.e. the fraction of the substance being evaluated in the
product/article) and the amount of product used per application. In fact, these two
parameters will often require product-specific data since the default values are very
general. For example, a default product ingredient fraction of 0.6 (60%) for dishwashing products (PC 35-1) may only be correct for some ingredients.
6
46
Technically, it is only necessary to enter reference values for the pathway, for which exposure estimation is
carried out in the PC/AC chosen (this can be checked in the “Defaults” worksheet). For example, only
inhalation exposure is considered relevant for PC 3-1 (Aircare, instant action (aerosol sprays)), so that only an
inhalation reference value has to be entered. However, to avoid error messages and to be able to evaluate
different products for the same substance, it is easier to enter all reference values at the start (if available).
June 2010
Figure 2-1
Printscreen of the “user input” worksheet (only first PCs shown with all sentinels and all subcategories selected)
The results are automatically calculated upon user input and can be accessed by choosing
one of the five results tabs (see above). The presentation of the results and the level of detail
vary somewhat between the different worksheets. For example, results by sentinel product
provide an overall view with exposure estimates and RCRs (the latter in red if they are above
1) for the PC/AC resulting in the highest estimate (worst-case scenario). Very helpful is the
functionality at the top of the worksheet, where users can display (“unhide”) and hide details
of the calculations.
The results by product sub-category also mark RCRs above 1 in red. In contrast to the
results by sentinel product, this worksheet not only displays results for all sub-categories
chosen for calculation but also gives the additional information whether the worst-case
scenario is based on exposure of adults, children or both. This overview by sub-category
does not display any details of the calculation but is helpful, e.g. in judging whether only the
one sub-category in the PC/AC shows high RCRs, while safe use can be demonstrated for
all other sub-categories.
47
June 2010
The three worksheets containing the route-specific results per sub-category, finally, are
different from the result presentations mentioned above in that only the exposure estimate is
presented (with all details), but not the risk characterisation. They are essential in
comprehending the calculations, which is facilitated by the algorithm shown in the header
(this information is also accessible in the sentinel products results via the “unhide” function
(see above), but only for the worst-case scenario and not all sub-categories selected). This
can be very useful in identifying the parameters that have an important impact on the
exposure estimate. The following figure 2-2, for example, shows that the default value for the
amount of PC 1 product used is the most crucial parameter for the inhalation exposure
estimate (for the concentration, the default amount alone is responsible for the differences).
Info-Box 11
It is not the intention of this guide to review and discuss the algorithms and default values
used in the tool. These are documented in the Technical Report (ECETOC 2009).
Generally, the default input parameters are based on ConsExpo fact sheets (see chapter
2.2.3) or expert judgement. However, the source/rationale of some of the default values is
not immediately evident. For example, a default frequency of 1 event/day has been
chosen for almost all sub-categories, although the ConsExpo fact sheets given as a
source generally contain more specific data. While this default is certainly conservative for
most uses, a few products (e.g. dishwashing liquids) may be used more often. The user
should discuss the frequency in the context of comparison with reference values (see
below).
The new algorithm for dermal exposure estimation does not require a migration factor (see
dermal scenario B in Chapter 2.2.1.2). This is achieved by assuming an (imaginary) layer
of a product/article in contact with the skin, for which the thickness is included in the tool.
The tool assumes complete transfer of the substance contained in this layer.
48
Glues, hobby
use
x
A
x
FQ
x
x
IR
x
1000)
/ (V
x
BW)
Exposure
(mg/m3)
Exposure
(mg/kg/day)
Body Weight
(kg)
Room
Volume
(m3)
ET
x
Conversion Factor
F
Inhalation Rate
(m3/hr)
Exposure
Time
(hr)
Algo- (PI
rithm:
Fraction Released
to Air1
(g/g)
Parameter:
FreQuency of Use
(events / day)
Product
Subcategory
Amount Product
Used per
Application
(g/event)
Descriptor
Product Ingredient
(g/g)
June 2010
0.3
9
1
1
4.0
1.4
1000
20
60
1.23E+01 1.35E+02
0.3
15000
1
1
6.0
1.4
1000
20
60
3.08E+04 2.25E+05
Glue from spray
0.3
255
1
1
4.0
1.4
1000
20
60
3.50E+02 3.83E+03
Sealants
0.3
390
1
1
4.0
1.4
1000
20
60
5.35E+02 5.85E+03
PC1:
Adhesives, Glues DIY-use
sealants
(carpet glue, tile
glue, wood
parquet glue)
Figure 2-2
Screenshot for inhalation exposure results for PC 1 products (default values used for input;
partly reformatted for better display).
Note that in this result presentation red values have nothing to do with risk characterisation
but highlight those parameters that are open to user input.
If a substance in several products has to be assessed, it is helpful to run the tool for all
PCs/ACs and all sub-categories. This approach is also useful if a particular product might not
be directly matched by one of the sub-categories available but may be represented by a
surrogate sub-category (obviously, this requires review and, if applicable, changes in the
default values). In addition, estimates for similar sub-categories can be compared and add
confidence in the exposure estimation.
For this purpose, it appears to be a good idea, to generate a “default file” with all sentinel
products and all sub-categories selected. This can then form the basis for exposure
estimation for various substances. At the end, the user will have several files (one each per
substance) containing all exposure estimations and RCRs. However, if this procedure has to
be applied to many substances, the Integrated tool should be considered as an alternative. 7
The ECETOC TRA Consumer tool does not provide exposure estimates for several PCs and
ACs. These are assigned an “n” in the descriptor code and cannot be selected for the
estimation (i.e. the respective cells are not green and inserting an “x” is impossible). While
some of these PCs and ACs are obviously not relevant for consumer exposure estimation
(e.g. PC 19 (intermediates)) or outside the scope of REACH (e.g. PC 29 (pharmaceuticals)),
7
It is impossible to give a „cut-off“ value for the number of substances above which application of the Integrated
tool is indicated. As an orientation, it appears that screening 5-10 substances across all sub-categories is not
very time-consuming with the stand-alone ECETOC TRA Consumer tool.
49
June 2010
this does not apply to all PCs/ACs concerned. For example, anti-freeze and de-icing
products (PC4) clearly have the potential for consumer exposure but these cannot be
assessed with the tool. One workaround is to select a surrogate PC/AC or sub-category and
to adapt the input parameters. The ECHA Guidance (ECHA CSA 2010, Chapter R.12) gives
some advice in Appendix R.12-7 on surrogate categories. If surrogate categories are used,
the following should be considered:

Review the routes of exposure and input parameters in the “Defaults” worksheet

Adapt input parameters to actual use (e.g. with sector-specific data)

Document changes and discuss similarities and differences between use (actual use
vs. PC/AC selected)
Similar to the ECETOC TRA Worker tool, total exposure from all three routes of exposure
can be calculated in the Consumer tool. In the risk characterisation part (various columns in
the “Results by Sentinel Prod” and “Results by Prod Subcat” worksheets), total exposure is
divided by the worst-case reference value (defined in the User Guide as “generally the lowest
of the pathway-specific reference values”) to give an overall RCR. As the following (fictitious)
example shows, this approach might be completely misleading because it is possible that the
overall RCR is well above 1 even when all route-specific RCRs are below 1. This is due to
the possibility that an oral reference value (which will probably be the one most often
available) may be the lowest of all reference values (i.e. taken for comparison with total
exposure), while oral exposure itself is not expected to occur. The latter is not an exception
but rather the rule in the ECETOC TRA Consumer tool, since oral consumer exposure is by
and large restricted to small children’s mouthing behaviour (oral exposure of adults is only
expected to occur in one out of 46 sub-categories).
Exposure (mg/kg x d)
Dermal
Oral
10
Inhalation
Total
15
25
Reference value (mg/kg x d)
Dermal
Oral
Inhalation
Worst-case
50
10
20
10
RCR
Dermal
0.2
Oral
Inhalation
Total / Worst-case
0.75
2.5
It is therefore not recommended to use the overall RCR based on total exposure without
scrutiny. In some cases, expert evaluation of the route-specific RCRs might be more
appropriate.
Appendix F of the Technical Report (ECETOC 2009) describes several options for refinement, which ultimately increase the accuracy of the estimates. When many of these are
50
June 2010
applied (e.g. inclusion of air exchange rates and application of specific rather than default
values), the tool virtually becomes a “Tier 1.5” (ECETOC 2009) model, situated somewhere
between Tier 1 and higher tier models, such as ConsExpo. Many of these refinements
cannot be implemented in the tool but have to be calculated separately. For example, the
tool does not offer the possibility to enter air exchange rates (which makes sense since it is a
Tier 1 tool).
Finally, a word of caution is in place. With only one exception, the frequency of use is set to 1
event per day (i.e. no average over 1 week or 1 year is taken). The exposure estimates of
the tool thus basically refer to the exposure during this event on one day (e.g. during
application of a paint or while a child plays with a toy). The estimated exposure thus has to
be compared with an acute reference value, especially in cases in which daily use cannot be
expected. For example, it is highly unlikely that a consumer applies 15 kg of carpet glue per
day over an extended period of time (PC 1-2; this is the default value used in the tool).
Alternatively, for an intermittent exposure regime exposure can be averaged from the oneday value and compared with chronic reference values. This requires knowledge and
documentation of the frequency of use for the respective product.
As already mentioned, dermal exposure is calculated with a new algorithm, which avoids
inclusion of a migration factor. This algorithm calculates exposure by assuming a skin
contact area and a thickness of the layer of the product in contact with the skin. Together
with the default density of 1 g product/cm3, this results in the amount of product contributing
to exposure. Using the example of AC 8-3 (Tissues, paper towels, wet tissues, toilet paper;
default input values), it can be shown that this figure can deviate somewhat from the total
amount of product assumed in inhalation exposure estimation:
Dermal exposure
Inhalation exposure
Contact area
857.5 cm
Thickness of layer
0.01 cm
Density of product
1 g/cm3
Amount of product
8.572 g
2
5.7 g
While the deviation in the amount of product is not very large for a comparatively rough Tier
1 tool, the user should be clear about this difference resulting from the different algorithms
employed. In consequence, a mass balance check is clearly helpful in this context, especially

when default input values are altered by the user (e.g. the amount of product used for
inhalation exposure) and

for total exposure estimates (see discussion above) since the algorithms generally
assume 100% release of the substance, thus potentially resulting in “double counting”
in the total exposure estimate.
51
June 2010
In summary, the ECETOC TRA Consumer tool is very valuable in screening the exposure of
consumers and allows identifying exposure associated with a high risk. It contains many
default values and is easier to handle than the equations introduced in Chapter 2.2.1,
especially if many scenarios have to be assessed. In some cases, it leads to identical results
than the equations if the same input values are used (e.g. for inhalation exposure to
substances with a high vapour pressure, fraction released to air = 1). In other cases, results
are quite different, e.g. for substances with a low vapour pressure (fraction released to air
e.g. 0.01) since this factor is not considered in the simple equations.
2.2.3
Users of exposure estimation tools should keep in mind that most tools are of a very
conservative nature (i.e. in most cases they tend to the cautious, higher side of exposure
estimates) and that they are only validated to a limited extend and/or for some uses.
Application of higher tier models in particular will in many situations require in-depth
understanding of exposure estimation and expertise in handling the tools to avoid highly
inaccurate estimates.
The higher tier tool discussed in this section can, in principle, be used for substances as
such, substances in mixtures and substances in articles.
The software ConsExpo (version 4.1, available from: http://www.consexpo.nl, the manual
(Delmaar et al. 2005) is also available but has not yet been updated from version 4.0 to 4.1)
will be discussed here in more detail since it is widely used and provides several productspecific input data (available via the defaults database), the origin of which can traced back
in the “fact sheets” (see box above). It is therefore possible to assess, whether a ConsExpo
default value is conservative enough or overly conservative for the ES under examination (a
quality category is also assigned to each value). However, as will be shown below, the
complexity of the software and of consumer exposure itself make it difficult to perform
assessments without a certain level of experience and expertise in exposure assessment.
After starting the software, it is helpful to go through the four different sections of ConsExpo
from the top down:

Product & compound: basic data input (e.g. Molecular weight, POW and vapour pressure for the substance);

Exposure scenario: selection from defaults database (see below);

Exposure Routes: input of missing data (i.e. not provided by defaults database);

Output: Results, reporting and analysing function.
The defaults database contains the following product databases:
52
June 2010

Painting products;

Cosmetics;

Pest control products;

Cleaning and washing;

Disinfectants;

Do-it-yourself products.
For each product database, there are several product categories, and for each product
category there are several default products, for which one or more scenarios are defined (i.e.
many default input values are already included). This tree-like approach is for a machine
dishwashing powder:

Cleaning and washing (product database);
o
Dishwashing products (product category);

Machine dishwashing powder (default product);

Loading (scenario).
One of the main advantages of ConsExpo is that default values are included for many scenarios (see below) and that the route to consider and the most appropriate model is selected
once the scenario is chosen. For example, once the loading scenario is selected in this
example, the input screen identifies inhalation exposure as the route (indicated by question
marks, i.e. data entry is required) and states the model (Exposure to vapour: instantaneous
release) (Figure 2-3, left).
If, on the other hand, the post-application scenario is chosen for the same default product,
the input screen indicates that oral exposure needs to be considered with the model “Oral
exposure to product: direct intake” (Figure 2-3, right).
53
Figure 2-3
June 2010
Print screen showing route of exposure to be considered and model applied in ConsExpo:
machine dishwasher powder, loading (left) and post-application (right)
The following Table 2-1 shows the input parameters for the example of loading the machine
dishwashing powder (substance-specific data have been omitted) with values to be chosen
by the user in italics. Of these,

the uptake fraction refers to the fraction available for systemic uptake and is set to 1
since an external exposure should be calculated,

the weight fraction of the compound (substance) is known from product-specific data.
This example also shows
the type of default data that
users can expect in ConsExpo, e.g. the exposure
frequency (252 uses of machine dishwashing powder
per year), duration (0.25
min. for loading the powder
in the dishwasher) and the
room volume (1 m3 set as
default to model inhalation
exposure in the immediate
vicinity of the source).
54
Info-Box 12
A closer look at the default input values in Table 2-1
identifies a very small applied amount of only 0.27 µg. An
inexperienced user would probably overwrite this with a
higher value. However, this is the amount of dust
generated by 200 g of powder (derived from laundry
powder; Proud’homme et al. 2006). This demonstrates that
information from the “fact sheets” (in this example:
Proud’homme et al. 2006) is often required when using
ConsExpo. More generally, it shows that expertise in
exposure assessment and an understanding of the
parameters and models involved is necessary to use
ConsExpo.
June 2010
Table 2-1:
Example of data input for ConsExpo: loading of a machine dishwashing powder containing 1%
of the substance under assessment (values to be chosen by the user are in italics)
Input parameter
Value
Unit
Exposure frequency
252
1/year
Body weight
65
kilogram
Inhalation model
Exposure to vapour: instantaneous release
Weight fraction compound
0.01
fraction
Exposure duration
0.25
minute
Room volume
1
m3
Ventilation rate
2.5
1/hr
Applied amount
2.7E-7
gram
Uptake model
Fraction
Uptake fraction
1
fraction
Inhalation rate
24.1
litre/min
General Exposure Data
Note:
the model also calculates the dose and therefore requires data (e.g. inhalation rate), which are not necessary for
estimation of the substance concentration in air.
The example shown above is a more sophisticated Tier 0 model (instant release assumed as
in Tier 0, but now with room ventilation).
It is another strength of ConsExpo, that input values (including the ones set as defaults in the
database) can be changed. In this respect, the sensitivity function in the output section may
also be helpful. For example, it allows users to model the concentration of the substance in
the air in dependence of the room volume.
The above example refers to a mixture but ConsExpo can also be used to model exposure to
a substance from an article. For example, dermal exposure in the post-application scenario
for the default product “detergent powder” (laundry powder) can be estimated using the
“Direct dermal contact with product: migration” model. While some default values are set in
this model, the important parameter of the leachable fraction requires consultation of the
respective “fact sheet” (Proud’homme et al. 2006).
In principle, ConsExpo may also be used for modelling exposure without using the defaults
database (e.g. dermal exposure to a substance used in textile finishing with the migration
model mentioned above). However, this requires a very clear understanding of the models,
the influence of the different parameters and the user must identify adequate values for all
input parameters.
55
June 2010
Info-Box 13
ConsExpo allows the user to use distributions rather than point values for many input
parameters (e.g. if the mean and standard deviation of a parameter is known). The
software can then perform probabilistic (Monte Carlo) calculations.
A special case is the particle size distribution of a product, which has an important
influence on inhalation exposure to spray and can be entered in the respective model.
This, however, is not a distribution in the above sense and does not allow Monte Carlo
calculations.
Industry has developed several default values, which could be used in addition to the
ConsExpo default values. For example, AISE (International Association for Soaps,
Detergents and Maintenance Products; http://www.aise.eu) provides detailed “habits and
practices” default values for consumers (e.g. on the amount of household product used and
the duration and frequency of use).
Other tools
The European Union System for the Evaluation of Substances (EUSES) software (version
2.1, available from: http://ecb.jrc.it/euses/) is another software package that allows to
estimate exposure for almost all impact areas, including consumers. If more complex models
are required for consumer exposure assessment, EUSES is referring to ConsExpo.
ECHA CSA 2008 mentions several software tools provided by the U.S. Environmental
Protection Agency; (e.g. E-FAST (Exposure and Fate Assessment Screening Tool, which
includes CEM, Consumer Exposure Model), MCCEM (Multi- Chamber Concentration and
Exposure Model) or WPEM (Wall Paint Exposure Assessment Model), available at
http://www.epa.gov/opptintr/exposure/index.htm, see also Appendix R.15-3 “Computer tools
for estimation of consumer exposure” in ECHA CSA 2008) that might be useful for higher tier
exposure estimation. These models require the same or even more experience than
ConsExpo.
Also, the British Aerosol Manufacturers' Association (BAMA; http://www.bama.co.uk/) has
developed a tool (BAMA Indoor Air Model) to estimate aerosol exposure from sprays under a
wide range of conditions of use. The user guide contains generic examples as well as advice
on model application and use of the estimates in Chemical Safety Assessments.
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June 2010
2.2.4
Refinement of consumer exposure estimation
If safe use cannot be demonstrated with the higher tier tools discussed in the previous
section, a refinement of the exposure estimation will become necessary. This may take
several forms, for example:

consideration of (product-integrated) RMMs (if not already considered when drawing up
the ES), e.g. if a product is placed on the market in pellet or granular form, inhalation
exposure may be assumed to be lower than the one to dust generated by handling
powders

substitution of the default input values in ConsExpo with more product-specific or ESspecific data (if it can be justified): consult the respective ConsExpo “fact sheet”, if
available, and assess input parameters,

use of specialised modelling tools, e.g. for estimating the migration of a substance from
an article (e.g. for migration from plastic and polymer food contact materials:
http://www.inra.fr/Internet/Produits/securite-emballage),

use of measured exposure data (check e.g. data in the EIS-ChemRisks project:
http://web.jrc.ec.europa.eu/eis-chemrisks/),

generation of measured data, especially for critical input parameters, such as
‒
the particle size distribution for inhalation exposure to sprays: an extensive list of
available methods can be found in Chapter R.7.1.14 (“granulometry”) of ECHA
CSA 2008.
‒
the release of a substance from an article for the dermal migration models:
consult BfR (2007) for a brief discussion of methods used to determine migration
of chemicals from textiles (this paper also contains default values for textile dyes
and auxiliaries),
‒
the release of a substance from an article (leachable fraction) for mouthing
scenarios: consult van Engelen et al. (2006, Chapter 4) for a detailed discussion
of the different methods available.
‒
There are several norms for the determination of migration from articles (partly
discussed in the overviews mentioned above), e.g.

“DIN EN 71-10: Safety of toys – Part 10: Organic chemical compounds Sample preparation and extraction”,

“DIN EN ISO 105-E04 (draft standard): ”Textiles – Tests for colour fastness Part E04: Colour fastness to perspiration” and

“DIN EN 1186-3: Materials and articles in contact with foodstuffs – Plastics –
Part 3: Test methods for overall migration into aqueous simulants by total
immersion”; available e.g. from http://www.beuth.de.
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June 2010
The approach taken for a refinement of the exposure estimation ultimately depends on the
nature of the ES under examination and requires expert knowledge in exposure assessment
(and other disciplines) both to choose the most meaningful strategy and in the interpretation
of results.
2.2.5
Combined uptake
As a final step in the exposure estimation, combined uptake (usually separately for acute and
long-term exposure) should be assessed. This involves two cases:

If consumers are exposed to one particular product via different routes of exposure
(e.g. inhalation and dermal), the combined uptake has to be determined (summation of
doses).

If consumers are exposed to different products containing the same substance and if
these products are likely to be used in parallel, the uptake of the substance from these
different products may be summed up. (In practical terms, this can be achieved only in
those cases, in which the registrant is aware of this situation, for example where known
downstream users prepare several products, which can in principal be used in parallel,
and he receives respective up-stream information.)
More advice on this step is given in ECHA CSA 2008 (Part E, Chapter 3.5; “Step 5:
combined exposures”).
2.2.6
Special case: Humans exposed indirectly via the environment
Exposure of humans via the environment results from the consumption of food and drinking
water, inhalation and soil ingestion (only relevant in specific situations). It is estimated on the
basis of predicted environmental concentrations (PECs) of the substance in (surface) water,
groundwater, air and soil. Methods to estimate PECs are described in the chapter on environmental exposure estimation (Chapter 3).
2.3
According to REACH, Annex I, the risk characterisation should assume that risk
management measures as described in the exposure scenarios are implemented. In this
respect the REACH text does not discriminate between consumers and workers. This
approach has been criticised (de Bruin et al. 2007), as compliance with instructions and
recommendations for use of personal protection measures may be limited, thus leading to
risks for relevant parts of the population. As it is undisputable that severe health risks for
consumers should be avoided, adequate control of risks should not rely on risk management
measures in those cases, in which non-compliance with risk management measures may
give rise to severe health effects such as corrosion or respiratory sensitisation. For such a
differentiation according to severity of effects, methodological proposals in ECHA CSA 2008
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(Part E, Chapter 3.4) may give some guidance: for qualitative risk assessment substances
are assigned to groups of “high”, “moderate” or “low” hazard according to their classification.
As explained in Chapter 3.1, Part I of the practical guide, in the risk characterisation part of
the chemical safety assessment information on exposure is compared with the hazard data
for a specific substance. In this step, exposure estimates are compared to the dose levels
without (or with low) concern (i.e. DNELs, derived no effect levels, or DMELs, derived
minimal effect levels, for substances without threshold). This process, relying heavily on
expert judgement and experience, is described here only in general terms. For a more
detailed description of approaches the reader is referred to ECHA CSA 2008 (Part E).
Risks for humans are considered to be adequately controlled if
the RCR (risk characterisation ratio) = exposure level / DNEL < 1,
i.e. the DNEL exceeds the exposure level.
Tier 0 models as explained in Chapter 2.2.1 result in various types of exposure estimates.
The following table contrasts these types of estimates with the corresponding types of
DNELs (for types of DNELs see also ECHA CSA 2008, Chapter R.8).
Table 2-2
Types of exposure estimates (Tier 0) and corresponding types of DNELs for the general population
Exposure estimate
DNEL
Cinh: concentration of the substance in the room
[mg/m3] (either acute or long-term)
DNEL acute inhalation
Lder: dermal load: amount of substance on skin
area per event [mg/cm2]
DNEL acute dermal local (presumably rarely
available)
Dder: dermal dose: amount of substance that can
potentially be taken up [mg/kg body weight and
day]
DNEL long-term dermal
Doral: intake of the substance [mg/kg body weight
and day] (either acute or long-term)
DNEL acute oral
DNEL long-term inhalation
DNEL long-term oral
In the case of substances with non-threshold effects, for which a DMEL has been derived,
exposure levels below the DMEL characterise a low, tolerable risk. DNELs/DMELs should be
derived for all critical endpoints and pathways.
When exposure to a substance in a specific setting occurs via several exposure routes or
when different products contain this substance, leading to exposure of humans, these combined exposures should be considered. This can be done either by summing up exposure
doses and comparing the total exposure with an adequate DNEL or by adding up RCRs
calculated for individual pathways or situations.
In some cases, there may be information on toxic effects for some endpoints, but no data to
allow derivation of a DNEL or DMEL. ECHA CSA 2008 (Part E, Chapter 3.4.1) in this regard
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mentions acute toxicity, irritation/corrosion (skin and eyes), sensitisation, mutagenicity and
carcinogenicity. In this case, a qualitative risk characterisation has to be carried out with the
aim to show adequate control of risks. Guidance on how to carry out such an assessment
can be found in ECHA CSA 2008 (Part E, and Chapter R.8).
2.4
Communication of the results in exposure scenarios and scaling
The risk characterisation leads to a description of the use conditions (operational conditions
of use and risk management measures), under which safe use of the substance can be
shown. These use conditions form the essential part of the exposure scenario, which is
communicated down the supply chain.
The information of the ES has to be used by the downstream user (DU), e.g. a company
using a substance to produce a consumer product, to check whether his substance use is
within the conditions of use considered by the registrant (“compliance check”). The registrant
can provide the DU with scaling methods as a part of the ES. Scaling methods are simple
equations by which the DU can demonstrate that he operates within the conditions of the ES
even if (some of) his conditions of use differ from those described by the registrant. Scaling
and related tools are described in Part I of the practical guide, chapter 7.7.
Please note: application of scaling is only possible if the registrant provides the respective
equations and a transparent description of his exposure estimation.
Example:
Consumer exposure to a volatile substance from use in a mixture has been calculated. The
registrant assumed complete evaporation of the substance contained in the mixture and
homogeneous distribution in room air to calculate the inhalation exposure concentration.
Both room size and the amount of substance in the mixture are linearly correlated with the
exposure concentration. This has been made transparent by the registrant who also gave
the following scaling rules in the ES:
1. Exposure concentration inversely linearly correlated to room size;
2. Exposure concentration linearly correlated to concentration of substance in mixture;
3. Exposure concentration linearly correlated to amount of mixture used.
A manufacturer (downstream user) of an adhesive mixture for consumer uses the substance
in higher concentrations. But the amount of mixture used is substantially lower. By applying
scaling rules 2 and 3 he is able to show that his use is compliant with the ES, even when
some conditions of use are not met:
Values given by the registrant in the exposure scenario:
60
Concentration of substance Y up to 20% (w/w), amount to be used: up to 10 g
June 2010
(single application).
Conditions of use for the adhesives consumer product:
-
Concentration of substance Y in product is 40% (w/w), amount to be used per
single application 1 g (single application).
To show compliance with the exposure scenario the manufacturer of the adhesives product
may
1. either use the algorithms, if provided by the registrant with his own input values to
recalculate the exposure under his own conditions of use, or
2. (based on linearity of the associations stated by the registrant) argue that the 2-times
higher concentration of Y in the product is outweighed by the 10-times lower amount
used per application.
Linear correlations are the most easily applicable scaling rules. Examples for determinants
linearly related to exposure can be (but may depend on the ES and the exposure model
used):

Room volume (up to a certain limit, as long as homogenous distribution can be
assumed);

Amount used;

Concentration in the mixture;

Exposure duration;

Application area for coatings.
Scaling of non-linearly correlated determinants generally requires application of more
complicated exposure models or other tools, which should be clearly described and provided
by the registrant, when proposing such scaling rules.
2.5
References
Api, A. M., Basketter, D. A., Cadby, P. A., Cano, M. F., Ellis, G., Gerberick, G. F., Griem, P.,
McNamee, P. M., Ryan, C. A., Safford, R.; Dermal sensitization quantitative risk assessment
(QRA) for fragrance ingredients; Regulatory Toxicology and Pharmacology, 52, 2008, 3-23
BfR, Bundesinstitut für Risikobewertung; Introduction to the problems surrounding garment textiles;
BfR Information No. 018/2007; Berlin, Germany
Bremmer, H. J., van Veen, M. P.; Children's Toys Fact Sheet. RIVM Report 612810012/2002; RIVM,
Rijksinstituut voor Volksgezondheid en Milieu, Bilthoven, Netherlands; 2002
61
June 2010
Bremmer, H. J., Prud'homme de Lodder, L. C. H., van Engelen, J. G. M.; General Fact Sheet. Limiting
conditions and reliability, ventilation, room size, body surface area. Updated version for
ConsExpo 4. RIVM report 320104002/2006; RIVM, Rijksinstituut voor Volksgezondheid en
Milieu, Bilthoven, Netherlands; 2006
de Bruin, Y. B., Hakkinen, P., Lahaniatis, M., Papameletiou, D., del Pozo, C., Reina, V., van Engelen,
J., Heinemeyer, G., Viso, A. C., Rodriguez, C., Jantunen, M.; Risk management measures
for chemicals in consumer products: documentation, assessment, and communication
across the supply chain; Journal of Exposure Science and Environmental Epidemiology, 17,
Suppl. 1, 2007, S.44-55
Delmaar, J. E., Park, M. V. D. Z., van Engelen, J. G. M.; ConsExpo 4.0. Consumer Exposure and
Uptake Models Program Manual. Report 320104004/2005; RIVM, Rijksinstituut voor
Volksgezondheid en Milieu, Bilthoven, Netherlands; 2005
Prud’homme de Lodder, L. C. H., Bremmer, H. J., van Engelen, J. G. M.; Cleaning Products Fact
Sheet. RIVM report 320104003/2006; RIVM, Rijksinstituut voor Volksgezondheid en Milieu,
Bilthoven, Netherlands; 2006
ter Berg, W., Bremmer, H. J., van Engelen, J. G. M.; 2007; Do-It-Yourself Products Fact Sheet. RIVM
report 320104007/2007; RIVM, Rijksinstituut voor Volksgezondheid en Milieu, Bilthoven,
Netherlands; 2007
van Engelen, J. G. M., Park, M. V. D. Z., Janssen, P. J. C. M., Oomen, A. G., Brandon, E. F. A.,
Bouma, K., Sips, A. J. A. M., van Raaij, M. T. M.; Chemicals in Toys. A general methodology
for assessment of chemical safety of toys with a focus on elements. RIVM/SIR Advisory
Report 0010278A01; RIVM, Rijksinstituut voor Volksgezondheid en Milieu, Bilthoven,
Netherlands; 2006
62
June 2010
3
Environmental exposure estimation
3.1
Aim of the environmental exposure estimation and risk characterisation
The purpose of carrying out environmental exposure estimation is to derive the predicted
environmental concentration (PEC) for environmental compartments of interest, i.e. water,
sediment, soil, air and top-predators, which are then compared with the Predicted No Effect
Concentrations (PNEC).
The first step in environmental exposure assessment is to estimate the quantities of the
substance released to the environmental compartments water, sediment, air, soil and top
predators during all life cycle stages of the substance. These emissions result in an exposure
of the environment. Release estimations may be based on measurements, on pre-defined
environmental release classes, on expert judgement or on IT based calculations. The second
step is the exposure estimation in order to derive predicted environmental concentrations
(PECs) for all environmental compartments. PECs are derived either by measurement
(monitoring data) or by model predictions taking into consideration distribution and fate
processes after the chemical has entered the environment.
Environmental exposure assessment encompasses the following targets:

Fresh surface water (including sediment);

Marine surface water (including sediment); 8

Terrestrial ecosystem;

Top predators via the food chain (secondary poisoning);

Micro-organisms in sewage treatment systems;

Atmosphere – mainly considered for chemical with a potential for ozone depletion,
global warming, ozone formation in the troposphere, acidification;

Man indirect, i.e. man exposed via the environment.
In the subsequent risk characterisation, the PEC values are then compared with the
Predicted No Effect Concentrations (PNEC). The PNEC for a specific environmental
compartment is regarded as a concentration below which adverse effects on ecosystems will
not occur. The PNEC is derived from toxicity test endpoints (e.g. LC50s or NOECs) using
appropriate assessment factors.
For some substances (e.g. inorganic substances & metals), the standard environmental
exposure assessment including risk characterisation by PEC/PNEC ratios and the guidance
materials on these methods may not be applicable as these guidance materials are mainly
8
Risk assessments for the marine environment are only required for specific industrial sites that release
wastewater directly into the sea.
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June 2010
focussed on organic chemicals 9 . A “Metals Environmental Risk Assessment Guidance”
(MERAG) has been developed presenting scientific concepts for assessing the risk posed by
the presence of metals and inorganic metal compounds in the environment. 10
Other substances may exhaustively be removed from the wastewater by chemical processes
like oxidation, neutralisation, precipitation, etc. Environmental exposure assessments for
these substances could be done on basis of measured release and exposure data.
3.2
Approaches to environmental exposure assessment
The environmental exposure assessment follows the following workflow:
1.
Release estimation (measured or calculated data) taking into account applied risk
management measures (e.g. biological / chemical waste water treatment)
2.
Consideration of distribution and fate processes (e.g. degradation) in the environment
3.
4.
The workflow for an environmental exposure assessment with a subsequent risk characterisation is illustrated in Figure 3-1.
9
For several inorganic substances / metals (i.e. ZnO, CdO, etc), EU Risk Assessments on the basis of
PEC/PNEC ratios are already available, thus indicating that the PEC/PNEC approach is not only applicable for
organic substances but also for inorganic substances and metals. The available RAR (see
http://ecb.jrc.ec.europa.eu/esis/index.php?PGM=ora) can give guidance how to perform risk assessments for
inorganic substances / metals.
10
http://www.icmm.com/page/1185/metals-environmental-risk-assessment-guidance-merag
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June 2010
Environmental Exposure Estimation
Risk
management
measures
Risk
Characterisation
Dilution,
Distribution,
Degradation
PEC in
Release
Air
STP
Release estimation:
- Measured data
- Environmental release
classes (ERC)
- Emisison scenario
documents (ESD)
- DU info
- IT based calculation
Wastewater treatment:
- Measured data
(influent – effluent)
- Modelling
Water,
Soil
Sediment
PEC/PNEC
PEC derivation:
- Measured data (monitoring)
- Estimation tools/model
prediction
Abbreviations: STP: sewage treatment plant; DU: downstream user
Figure 3-1
3.2.1
Environmental exposure assessment and risk characterisation
Release estimation
As mentioned above release estimation is the first step in environmental exposure
assessment. Emissions into the environment may occur as a result of any process or activity
during the life cycle of a chemical i.e. manufacture, formulation, industrial/professional/private
use, service life & waste treatment.
Concerning the emission pattern it needs to be distinguished between distribution on the
local and on the regional scale. Local emissions are assessed in the vicinity of point sources
and are expressed as daily average concentrations. Regional emissions are not calculated
for single emission sources, but for larger areas over a longer time period, thus representing
background concentrations of a substance. Regional exposure estimation is based on yearaveraged emissions to water, air and soil. The relationship between regional and local scale
emissions is illustrated in Figure 3-2.
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June 2010
Regional environment:
Densely populated area of 200 x 200 km with 20 million inhabitants where 10% of the European
production and use take place
Background
concentration
Figure 3-2
Local environment: vicinity of one point source e.g. one production site
Relationship between regional and local scale
Determinants of release
Key determinants of substance release resulting in environmental exposure are:

Quantity of substance applied in a use or a process per time;

Emission pathways (i.e. emission to water, air, soil, or (solid) waste);

Release / emission factors from processes and products (before abatement); 11

Efficiency of any abatement or control technology that reduces the emission to air,
water, soil or (solid) waste;

Spatial dispersion of emission sources (local or regional emissions);

Duration of emission (e.g. working days per year).
11
66
Release / emission factors: the fraction of the substance emitted from the process or use to (waste) water,
(waste) air, soil, or (solid) waste before onsite or offsite abatement measures.
June 2010
How to assess release / emissions to the environment
Measured release information of substances might be easily obtained for the first three life
cycle stages (LCSs): (i) Production, (ii) Formulation, and (iii) Industrial Use because this
information often is laid down in the licence(s) supplied by the authorities. Before using
measured data, it needs, however, to be considered if they cover the use(s) described in the
exposure scenario (ES). Measured data are not preferable per se but have to meet certain
criteria, as it is the case for modelling. For general criteria on measured data please refer to
Chapter 1.2.1 above. Additional criteria to be fulfilled by measured data are listed in the
subsequent chapter “Use of measured data“.
For the remaining LCSs the availability of measured data is expected to be quite limited and
consequently the emissions to the environment need to be estimated with appropriate
methods. Several release estimation methods are available. As already discussed in Chapter
1.2.1, the level of differentiation, and thus the input requirements, increase from a lower tier
(level 1) to a higher tier (level 2). This step-wise approach ensures that a more detailed,
labour-intensive assessment is not carried out for situations, in which negligible exposure is
expected.
The following methods are suitable for Tier 1 assessments:
1.
2.
Calculation (either manual or IT-based e.g. with the tool EUSES) of the environmental
release using given basic equations (Guidance document Chapter R.16, equations
R.16-1 and R.16-2).
a)
Key input parameters to these equations are listed above as “determinants of
release”.
b)
For an initial Tier 1 assessment, pre-defined release/emission factors can be taken
from the newly developed Environmental Release Categories (ERC) presented in
the Guidance document Chapter R.16 (Appendix R.16-1, Tables R.16-20 until
R.16-23). These ERCs specify default emission factors for different life cycle
stages of chemicals i.e. the fraction of a substance emitted from the process or
use considered to (waste) water, (waste) air, soil, or (solid) waste before
abatement measures (for a more detailed description see below). The ERC
method does not require any explicit substance information. The concept of ERCs
within the Use Descriptor System is described in Part R.12 of the ECHA Guidance
(Section R.12.3.4, Appendices R.12.4.1 and R.12.4.2).)
Branch-specific OECD and EU Emission Scenario Documents (ESDs) including
generic scenarios by US EPA (US EPA OPPT Generic Scenarios
(http://www.epa.gov/oppt/exposure) might be used instead of ERCs but are not yet
available for all industrial uses.
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June 2010
3.
Generic exposure scenarios (GES) and further branch-specific information as
developed by sector groups (see Chapters 9.7 and 10 of the practical guide).
4.
Use specific information on emission; either based on measurements or downstream
user (DU) information, expert judgement or more precise process descriptions.
Use of Environmental Release Categories (ERC)
Environmental Release Categories (ERC) have been established to facilitate the derivation
of release/emission factors for an initial Tier 1 assessment (Guidance document Chapter
R.16, Tables R.16-22 and R.16-23). For each ERC default emission / release factors to air,
water and soil have been defined based on the assumption that no risk management
measures are in place. These release/emission factors are then used as input into equations
R.16-1 and R.16-2 for the calculation of the environmental release. The selection of the
appropriate ERCs needs basic information on the operational conditions of use of the
substance under consideration. In detail, knowledge on the following parameters is required
for the selection of the adequate ERC:

lifecycle stage of the substance i.e. production, formulation or use;

level of containment i.e. application in open or closed systems;

type of use in life cycle stages i.e. inclusion into/onto matrix, processing aid, intermediate, monomer etc.;

dispersion of emission sources i.e. industrial use or wide disperse use;

indoor use (connection to sewage treatment given) or outdoor use (no connection to
sewage treatment assumed).
For the selection of the adequate ERC and the derivation of the pre-defined release/emission
factors, no substance specific properties are required.
In addition to the release/emission factors, the ERCs include also pre-set values for the
percentage of the substance used as input to the emission calculation, the release time in
days per year assumed for the calculation as well as the dilution factor to be applied for the
subsequent PEC derivation (see Table R.16-23 of Guidance Chapter R.16).
Release estimation based on ERC can be regarded as a first conservative approach used for
a Tier 1 assessment under REACH.
If a risk is indicated in this Tier 1 assessment based on conservative release estimates, the
assessment of the release rates may be refined by using more precise data on risk
management measures. Furthermore, if detailed information on the identified uses is
available, a higher Tier assessment may be performed by using specific information on
marketing, use, release days or exposure of the substance. To refine the default emission
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June 2010
factors, branch-specific Emission Scenario Documents (ESDs), generic exposure scenarios
(GES) or other data sources like downstream user information are needed to improve the
initial exposure estimate.
Industrial sector groups can define more specific environmental release categories which
describe more precise the emission situation for specific processes. These categories are
called “specific Environmental Release Categories” (spERCs) (see section R.16.3.5 of the
ECHA Guidance on information requirements and the chemical safety assessment).
The present version of ECETOC TRA provides the option to use spERCs. The updated
integrated tool can be found at http://www.ecetoc.org/tra (last update: April 26, 2010).
Waste water treatment
One of the critical questions in the environmental exposure estimation (especially for the
aquatic environment) is whether or not the substance will pass through a wastewater
treatment plant before being discharged into the environment.
Many of the larger industrial installations are usually connected to a municipal wastewater
treatment plant or have treatment facilities on site. These treatment plants are not always
biological treatment plants but often physico-chemical treatment plants in which organic
matter is flocculated by auxiliary agents e.g. by iron salts followed by a sedimentation
process resulting in a reduction of organic matter (measured as COD 12 ) of about 25-50%.
The above-described situation is taken into account as follows in the environmental exposure
assessment:
On a local scale, wastewater may or may not pass through an STP before being discharged
into the environment. Depending on the exposure scenarios, an aquatic PEClocal with or
without STP can be calculated. In some cases, both may be needed if it cannot be
ascertained that local emissions will pass through the STP. The PEC without considering an
STP-treatment will only be used in the exposure estimation, when the substance considered
has a specific identified use where direct discharge to water is widely practised;
For a standard regional scale environment it is assumed that 80% of the wastewater is
treated in a biological STP and the remaining 20% released directly into surface waters.
The degree of removal in a wastewater treatment plant is determined by the physicochemical and biological properties of the substance (biodegradation, adsorption onto sludge,
sedimentation of insoluble material, volatilisation) and the operating conditions of the plant.
As the type and amount of data available on degree of removal may vary, the following order
of preference should be considered:
12
COD: chemical oxygen demand
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June 2010

Measured data in full scale STP:
The percentage removal should preferably be based upon the difference of measured
influent and effluent concentrations. As with measured data from the environment, the
measured data from STPs should be assessed with respect to their adequacy and
representativeness.

Simulation test data
Simulation testing is the examination of the potential of a substance to biodegrade in
a laboratory system designated to represent either the activated sludge-based
aerobic treatment stage of a wastewater treatment plant or other environmental
situations, for example a river.
The most common simulation tests on biodegradability of substances are “Inherent
biodegradability test” according to OECD Guideline 301 and “Ready biodegradability
tests” according to OECD Guideline 302.

Modelling STP:
If there are no measured or simulation test data available, the degree of removal can
be estimated by means of a wastewater treatment plant model. For the calculation
the following substance specific input data are required:
‒
octanol/water partitioning coefficient (log Kow);
‒
Henry's Law constant;
‒
results of biodegradation tests.
A wastewater treatment plant model (SimpleTreat) is implanted in exposure
estimation tool EUSES which is presented below.
3.2.2
Distribution and fate processes in the environment
As a second step of the environmental exposure estimation, the distribution and fate processes of the substance in the environment are considered. 13
After the release of a chemical into the environment, various partitioning, transformation
and/or degradation processes might take place resulting in that the chemical will be distributed in the various environmental compartments (air, soil, water, sediment, biota) at certain
concentration levels.
13
70
From a practical point of view, distribution and fate processes are mainly important for those cases where
initial exposure estimations show that the predicted environmental concentrations (PECs) exceed the
predicted no-effect concentrations (PNEC) indicating that the use is not safe. Consideration of distribution and
fate processes of a substance in the environment will result in lower PEC values and thus, in lower
PEC/PNEC ratios.
June 2010
To assess the environmental exposure, the following main distribution processes are
considered: 14

Volatilisation of substances with high vapour pressure;

Adsorption to soil, sediment and suspended matter;

Bioconcentration and biomagnification in humans and animals;

Transformation and degradation processes in the environment. Both biodegradation 15
and abiotic degradation (i.e. hydrolysis and photolysis) should be considered. If stable
and/or toxic degradation products (metabolites) are formed, these should be assessed
as well, at least to the extent information on the degradation products is available.
In order to assess the partitioning and degradation behaviour of a substance in the
environment, the following minimum information is required: molecular weight, water
solubility, vapour pressure, octanol-water partition coefficient and information on ready
biodegradability for the substance. For an inorganic substance, it is also advised to provide
information on the abiotic degradation, and solid-water partition coefficients and the waterbiota partition coefficients.
3.2.3
Exposure of the environment is the result of the release of substances, which may partly be
degraded/removed due to treatment facilities, subsequent distribution and degradation within
the environment. As output from the distribution and exposure calculations predicted
environmental concentrations (PECs) for the environmental compartments water/sediments,
soil and air are derived. In addition, secondary poisoning of predators and intake of man via
the environment is calculated based on the environmental exposure concentrations in water,
air, soil.
For some substances measured concentrations will be available for the environmental
compartments air, fresh or saline water, sediment, biota and/or soil. These data may have
been collected by environmental monitoring. They have to be carefully evaluated for their
adequacy and representativeness according to the criteria below before they are used for the
enrvironmental risk assessment. They are used together with calculated environmental
concentrations for the exposure estimation.
The evaluation of measured data should follow a stepwise procedure:
14
These processes are considered automatically by the exposure estimation tool EUSES.
15
Biodegradation takes place in the sewage treatment plant, in surface water, sediment and soil as well as in the
marine environment.
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June 2010

The reliability of the measured data should be checked by evaluation of the sampling
and analytical methods employed. A quality check of the applied measuring techniques
is necessary to decide whether the measured data are valid without restriction and may
be used for the exposure estimation or are only valid with restrictions any thus may
only be used to support the calculated exposure estimation. Chapter R.16 (Table R.164) lists quality criteria for the use of existing data.

The data should be representative for the environmental compartment of concern
meaning that the sampling frequency and sampling pattern should be sufficient to
adequately represent the concentration at the selected site. If the measured data are
results of sporadic examinations they are less representative than measurements of a
substance at the same site over a certain period of time. Measured concentrations
caused by an accidental spillage or malfunction should not be considered in the
exposure estimation.

Measured data should be assigned to local or regional scenarios by taking into account
the sources of exposure. Samples taken at sites directly influenced by an emission
should be used to describe the local scenario (PEClocal), while samples taken at larger
distances from emissions may represent the regional concentrations.
Both the mean concentration and the concentration range should be presented. If only
maximum concentrations are reported, they should be considered as a worst-case assumption, providing they do not correspond to an accident or spillage. However, the use of only
mean concentrations can result in an underestimation of the existing risk, because temporal
and/or spatial average concentrations do not reflect periods and/or locations of high
exposure.
The measured data should be compared to the corresponding calculated PEC. For naturally
occurring substances background concentrations have to be taken into account. For risk
characterisation, a representative PEC should be decided upon based on measured data
and a calculated PEC (see subsequent paragraph on “Calculated versus measured PEC
values”).
Calculated PEC values
PEC values for the aquatic and soil compartment as well as for the atmosphere are
calculated both for the local and for the regional scale. As mentioned before, the local scale
accounts for local emissions and the regional background concentration which is added to
this, whereas the regional scale accounts for overall emissions into a region.
The local concentration (PEClocal) close to a point source emission is calculated as the sum
of the concentration from the point source and the background concentration. The
background concentration or the regional concentration (PECregional) is calculated by
accounting for all releases over a wider, regional area and by accounting for the distribution
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June 2010
and fate of the chemical after the release to the environment. In obtaining the regional
concentration, the manufacturer/importer (M/I) has to account for all releases into the
environment for his supply chain. However, it can be useful on a voluntary basis to consider
exposure resulting from emissions of the same substance manufactured or imported by other
registrants (e.g. the overall estimated market volume).
In addition to predicted concentrations in environmental compartments, predicted concentrations in the food for predators, i.e. the concentration in worms and fish, may need to be
calculated (PECoral, predator) in order to estimate the potential of a substance for secondary
poisoning. Secondary poisoning is concerned with toxic effects in organisms in higher trophic
levels of the food web, either living in the aquatic or terrestrial environment, which result from
ingestion of organisms from lower trophic levels that contain accumulated substances. This
exposure route is relevant when there are indications for a potential bioaccumulation:
If, at production/import volumes between 1–100 tonnes 16 per year, a substance:

has a log Kow ≥ 3 and a molecular weight below 700 g/mol; or

is highly adsorptive; or

belongs to a class of substances known to have a potential to accumulate in living
organisms; or

there are indications from structural features;

and there is no mitigating property such as of hydrolysis (half-life less than 12 hours);
then there is an indication of bioaccumulation potential.
For the assessment whether secondary poisoning is a relevant exposure route, it is further
necessary to consider whether the substance has a potential to cause toxic effects if
accumulated in higher organisms. This assessment is based on classifications on the basis
of mammalian toxicity data, i.e. the classification Very Toxic (T+) or Toxic (T) or harmful (Xn)
with at least one of the risk phrases R48 “Danger of serious damage to health by prolonged
exposure”, R60 “May impair fertility”, R61 “May cause harm to the unborn child”, R62
“Possible risk of impaired fertility”, R63 “Possible risk of harm to the unborn child”, R64 “May
cause harm to breastfed babies”. Here it is assumed that the available mammalian toxicity
data can give an indication on the possible risks of the chemical to higher organisms in the
environment.
If a substance is classified accordingly or if there are other indications (e.g. endocrine disruption), an assessment of secondary poisoning should be performed.
16
REACH Annex IX indicates that information on bioaccumulation in aquatic species is required for substances
manufactured or imported in quantities of 100t/y or more.
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June 2010
As mentioned before, secondary poisoning describes the risk to (fish or worm eating)
predators and is calculated as the ratio between the concentration in their food (PECoralpredator) and the no-effect concentration for oral intake (PNECoral). The concentration of a
substance in food (fish or worm) is calculated on basis of its predicted environmental
concentrations in water or soil considering the bioconcentration factors (BCF 17 ) in fish or
earthworms as well as the respective biomagnification factor (BMF 18 ).
The indirect exposure of humans via the environment may also be determined in the
course of the environmental exposure assessment. An indirect exposure may occur by
consumption of food (e.g. fish, crops, mean or milk) and drinking water or by inhalation of air.
The output of the calculation is regional and local total human doses of the substance via the
environment.
An assessment of indirect exposure is generally only conducted if:

the tonnage >1,000 t/y; or

the tonnage >100 t/y and the substance is classified
‒
as “Toxic” with a risk phrase “R48”; or
‒
as a carcinogen or mutagen (of any category); or
‒
as toxic to reproduction (category 1 or 2).
Calculated versus measured PEC values
When PECs have been derived from both measured data and calculations, they should be
compared. If they are not of the same order of magnitude, analysis and critical discussion of
divergences are important steps for developing an environmental risk assessment. The
following cases can be distinguished:

Calculated PEC ≈ PEC based on measured concentrations
The result indicates that the most relevant sources of exposure were taken into
account. For risk characterisation, the value with the highest confidence should be
used;

Calculated PEC > PEC based on measured concentrations
This result might indicate that relevant elimination processes were not considered in
the PEC calculation or that the employed model was not suitable to simulate the real
environmental conditions for the regarded substance. On the other hand measured
17
BCF describes the bioaccumulation in aquatic species and is the ratio between the concentration in the
organisms and the concentration in the surrounding water. BCF is either measured or estimated on basis of
the logKow (n-octanol/water partition coefficient) using QSAR methods (see Guidance document Chapter
R.7c, Section R.7.10.3.2).
18
BMF is defined as the relative concentration in a predatory animal compared to the concentration in its prey
(BMF = Cpredator/Cprey).
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June 2010
data may not be reliable or represent only the background concentration or
PECregional in the regarded environmental compartment. If the PEC based on
measured data has been derived from a sufficient number of reliable and representative samples then they should override the model predictions.
Calculated PEC < PEC based on measured concentrations
This relation between calculated PEC and PEC based on measured concentrations
can be caused by the fact that relevant sources of emission were not taken into
account when calculating the PEC, or that the used models were not suitable. Similarly,
an overestimation of degradation of the compound may be the explanation. Alternative
causes may be spillage, a recent change in use pattern or emission reducing measures
that are not yet reflected in the samples.

If the measured values have passed the procedure of critical statistical and geographical
evaluation, a high degree of confidence can be attributed to those data and they shall
override the calculated PECs.
3.2.4
Quantitative risk characterisation
A quantitative risk characterisation is carried out by comparing the PEC with the PNEC 19
values deriving the so-called risk characterisation ration (RCR). This is done separately for
each of the following environmental protection targets:
Inland environmental protection targets:

aquatic ecosystem including sediment;

terrestrial ecosystem;

atmosphere; 20

micro-organisms in sewage treatment plants

fish- and worm-eating predators (secondary poisoning). 21
19
PNEC: Predicted no-effect concentration; methods for PNEC derivation from ecotoxicological tests can be
found in Chapter R.10: Characterisation of dose [concentration]-response for environment.
20
PECair cannot be compared with the PNEC for air because the latter is usually not available. However,
PECair is used as input for the calculation of the intake of substances through inhalation in the indirect
exposure of humans (PECair / DNELinhalation).
21
Exposure of predators is only relevant if the substance shows indications for bioaccumulation and has a
potential to cause toxic effects if accumulated in higher organisms (see paragraph “Calculated PEC values”).
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June 2010
For specific industrial sites that release wastewater directly into the sea, an additional risk
assessment for the marine environment is required. For inland industrial sites, however,
discharging their wastewater to rivers, marine risk assessments are not required.
Marine environmental protection targets comprise:

aquatic ecosystem including sediment;

predators and top predators (secondary poisoning).
A list of the different PEC/PNEC ratios (= RCR) that should be considered for the inland and
marine environments is given in Table 3-1 and Table 3-2, respectively.
Table 3-1
Overview of PEC/PNEC ratios considered for inland risk assessmenta)
Local
Regional
Water:
PEClocalwater / PNECwater
Water:
PECregionalwater / PNECwater
Sediment:
PEClocalsediment /
PNECsediment
Sediment:
PECregionalsediment /
PNECsediment
Soil:
PEClocalsoil / PNECsoil
Soil:
PECregionalagr.soil / PNECsoil
Microorganisms:
PECstp /
PNECmicroorganisms
-
Predators,
fish eating:
(0.5 x PEClocal,oralfish + 0.5 x PECregional,oralfish) / PNECoral
Predators,
worm-eating:
(0.5 x PEClocal,oralworm + 0.5 x PECregional,oralworm) / PNECoral
a)
These ratios are derived for all stages of the life-cycle of a compound. The regional risk characterisation for
each compartment is based on the sum of regional PNECs for all life-cycle stages. The PEC-local for each
life-cycle stage and compartment is based on the sum of the local concentration and the PEC-regional
(sum).
Table 3-2
Overview of PEC/PNEC ratios considered for marine risk assessmenta)
Local
Regional
Water:
PEClocalseawater /
PNECsaltwater
Water:
PECregionalseawater /
PNECsaltwater
Sediment:
PEClocalsediment / PNECmarine
sediment
Sediment:
PECregionalsediment / PNECmarine
sediment
Predators:
[(PEClocalseawater,ann + PECregionalseawater) x 0.5 x BCFfish x BMF1] /
PNECoralpredator
Top
predators:
[(0.1 x PEClocalseawater,ann + 0.9 x PECregionalseawater) x BCFfish x BMF1 x
BMF2] / PNECoraltop predator
a)
These ratios are derived for all stages of the life-cycle of a compound. The regional risk characterisation for
each compartment is based on the sum of regional RCRs for all life-cycle stages. The PEC-local is based on
the sum of the local concentration and the PEC-regional (sum).
For the air compartment usually only a qualitative assessment of abiotic effects is carried out.
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June 2010
As mentioned before, the indirect exposure of humans via the environment is also
determined in the course of the environmental exposure assessment. The output of the
calculation is regional and local total human doses of the substance via the environment.
These values are to be compared with the DNEL values for external exposure.
In case control of risks cannot be demonstrated the input parameters for the environmental
exposure estimation may be refined. If the necessary data are not available, further
information and/or testing may be required. A decision must be taken as to whether both the
PEC and PNEC will be iterated or only one of them. If additional information needs to be
generated, it should be based on the principles of lowest cost and effort, highest gain of
information and the avoidance of unnecessary testing on animals.
The following possibilities for refinement should be investigated:

Get more exact knowledge on the actual number of emission days and fraction of main
source by contacting the DU or the branch organisation of the DU

Get more exact knowledge on the actual emission fractions by contact to the DU or the
branch organisation of the DU

If the water solubility in the waste water is exceeded in the initial emission estimation,
then modify the emission fraction to waste water accordingly.

If the substance has a low Henry constant (< 1 Pa·m3/mol), then consider the emission
to air as of no importance.

Consider the introduction of (additional) RMMs to lower the releases to the
environment. When introducing the impact of an RMM, make sure that the RMM was
not already included in the applied emission factors. Quantify the effectiveness of
additional RMMs that decrease the overall emitted or released amounts.
Both, the release calculation and the exposure prediction can be further refined by measured
data, e.g. waste water concentrations or monitoring data for surface water. However, the
assessor should make sure that the CSR includes sufficient documentation that the
operational conditions and the RMMs described in the exposure scenario match the
conditions under which the measured data were obtained.
Qualitative risk characterisation
When no quantitative risk characterisation can be carried out, for example for remote marine
areas or when either PEC or PNEC cannot be properly derived, a qualitative risk characterisation should be conducted.
An environmental hazard assessment in accordance with REACH, Annex I, and the
estimation of the long-term exposure of the environment (Annex I, Section 5) cannot be
77
June 2010
carried out with sufficient reliability for substances satisfying the PBT and vPvB criteria. This
necessitates a separate PBT and vPvB assessment (Guidance document Chapter R.11). For
a qualitative assessment of risks for PBT and vPvB substances, the approach should be
used as described in Section R.11.2.2.
For some substances it may not be possible to undertake a full quantitative risk assessment,
using a PECwater/PNECwater ratio because of the inability to calculate a PNECwater. This
can occur when no effects are observed in short-term tests. However, an absence of shortterm toxicity does not necessarily mean that a substance has no long-term toxicity,
particularly when it has low water solubility and/or high hydrophobicity. For such substances,
the concentration in water (at the solubility limit) may not be sufficient to cause short-term
effects because the time to reach a steady-state between the organism and the water is
longer than the test duration. This is also the case for non-polar organic substances with a
high potential to bioaccumulate.
In summary it is recommended to conduct a qualitative risk assessment in order to decide if
further long-term testing is required in the following cases: for substances with log Kow > 3
(or BCF > 100) and a PEClocal or PECregional > 1/100th of the water solubility.
Also in cases where the logKow is not a good indicator of bioconcentration, or where there
are other indications of a potential to bioconcentrate (see ECHA Guidance Section R.7.10), a
case-by-case assessment of the presumable long-term effects will be necessary.
3.2.5
Exposure estimation tools – Tier 1
Environmental exposure estimation including release estimation, PEC calculation and risk
characterisation can be done with the software program EUSES or with the TGD excel sheet
which has been revised by ECETOC. It is the basis for the new ECETOC TRA tool (see
below). 22
EUSES (2.1) and a manual to the program can freely be downloaded from the internet
(http://ecb.jrc.it/euses). EUSES can be run on a normal PC.
For Tier 1 assessments, the information described in Appendix 4.3-1 should be collected
(more information on fate may be needed for inorganic substances).
EUSES has built-in models for conservative release/emission estimation. Instead of using
the standard EUSES release estimation, the newly developed ERCs (see chapter on
“Environmental Exposure Categories”) can be manually entered into EUSES. Alternatively,
release estimation can be done separately as indicated in Chapter 3.2.1 above, and the
calculated release estimates can then entered into EUSES for subsequent PEC calculations.
22
78
The TGD excel sheet has been revised by ECETOC together with Radboud University Nijmegen. The new
version of ECETOC TRA is available since autumn 2009. The old TGD is not state of the art anymore.
June 2010
The output of the Tier 1 exposure estimation consists of the predicted environmental
concentrations (PECs) for the different environmental compartments (see Appendix 4.3-2).
An example of environmental exposure calculation with EUSES is given in Appendix 4.3-2.
Environmental exposure estimations can also be made using the new version of ECETOC
TRA. For access and documentation of ECETOC TRA see Appendix 4.1-2, first line of the
table. The environmental exposure part of ECETOC TRA is based on the EUSES excel tool
which has been described above.
Environmental exposure calculations are in ECETOC TRA part of the so-called “integrated
tool” (for worker exposure and consumer exposure, stand-alone-versions are available within
ECETOC TRA in addition to the integrated tool.).
The new version of the exposure assessment tool ECETOC TRA (version 2) uses the same
input parameters as EUSES. It already contains the newly developed ERCs and offers the
possibility to use specific environmental release categories (spERCS). ECETOC TRA
provides the same output as EUSES.
The environmental tool of ECETOC TRA consists of two modules: release estimation and
calculation of the predicted environmental concentration (PEC). The release estimation
module starts with the environmental release categories (ERCs, see chapter chapter 9.3,
Part II of the Practical Guide). It offers four different alternatives to the ERCs: specific
environmental release categories, default values from the A tables and B tables of the earlier
Technical Guidance Document on Risk Characterisation of existing and new substances
(http://ecb.jrc.ec.europa.eu/tgd/), data from the OECD Emission Scenario Documents and
measured data (site specific emission data).
EUSES enables the user to perform all steps of the environmental exposure assessment
(including release estimation and refinement of risk management measures) as well as the
subsequent risk characterisation within the same software tool. For a conservative Tier 1
assessment only few input data are actually required. For many required parameters default
values are incorporated in the tool that may be overwritten if substance or process specific
data are available.
However, it is not easy to work with the current user-interface of EUSES as an unexperienced user, in particular where tonnage and use information data is to be specified.
The impact of information inputs on the overall results are not always transparent and easy
to understand. Also, it is not possible to trace to which extent risk management measures are
already assumed in the default emission factors. Thus iteration may lead for example to a
duplication of RMMs already included in the default emission factor.
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June 2010
These limitations are the reasons for introducing the Environmental Release Categories
(ERCs). The ERCs can be entered manually in EUSES. To introduce RMMs and changes in
the conditions of use, the presets for the ERCs can be replaced with own estimates, information from downstream users, expert judgements or measured data.
The correlations used for the derivation of substance parameters, i.e. mainly partition data,
are not valid for inorganics and surfactants. Whenever measured partition and degradation
data are available, these should be used in the calculations. This is of very high importance
for metals, inorganic compounds and surfactants.
With regard to the default values used in EUSES it needs to stressed that these should
critically be checked on their suitability to represent the actual situation of the M/I and/or DU.
If reliable and representative substance or process or site-specific data are available these
should be used to replace the given default values. For example, the discharge volume of a
sewage treatment plant (i.e. the outflow from a standard STP) is standardised in EUSES to a
volume of 2,000 m³/day. The effluent of the sewage treatment plant is discharged into
surface water (e.g. a river). By mixing processes the effluent is diluted in the surface water
assuming a default dilution factor of 10, i.e. the 2,000 m³/day are discharged in a river with a
flow rate of 18,000 m³/day resulting in a total surface water volume of 20,000 m³/day.
Experiences from the textile industry showed, however, that in reality the receiving water
bodies vary significantly, thus influencing the resulting PEC value significantly. In these
cases, site specific data should be used for the environmental exposure assessment.
In order to enable to relate to the calculation, all parameters and default values used for the
environmental exposure calculations must be documented. EUSES can prepare an
electronic report of all the input and output data in a Word or Excel format automatically.
CHESAR, the ECHA IT tool for preparation of chemical safety assessments and chemical
safety reports, will contain a tool for the environmental exposure estimation. It consists of a
specific release module and the EUSES fate model. The defaults in the release module
come from the earlier Technical Guidance Documents on risk assessment of existing and
new substances (http://ecb.jrc.ec.europa.eu/tgd/) (for a description of CHESAR see Part I of
this practical guide, chapter 3.5).
3.2.6
EUSES and TGD excel sheet calculations may be improved by refining some of the input
data.
Both, the release calculation and the exposure prediction can be further refined by measured
data, e.g. waste water concentrations or monitoring data for surface water. However, the
assessor should make sure that the chemicals safety report includes sufficient documentation that the operational conditions and the RMMs described in the exposure scenario
match the conditions under which the measured data were obtained.
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June 2010
Furthermore, at a higher tier in the risk assessment process more specific information on the
biodegradation behaviour of a chemical may be available that can be used to refine the
assumptions for the STP. Similar to EUSES; also in the environmental exposure part of
ECETOC TRA version 2 higher tier calculations can be made by using additional and more
specific input data.
3.2.7
Other tools for environmental exposure estimation
Other tools for environmental exposure estimation may be used for substances which are
applied in a way similar to a pesticide, for example as a fertilizer, or for substances which are
applied in offshore installations. For these substances, models recommended by FOCUS 23
or the CHARM model, 24 respectively, can be an alternative to EUSES/TGD excel sheet.
3.3
Scaling related to environmental exposure
A downstream user (DU) who receives the exposure scenario (ES) from his supplier needs
to check if his use is in compliance with the received ES. If several of his conditions of use
differ from the ES it is not always apparent whether or not his use is covered by the ES. In
order to allow this compliance check the supplier of the ES should communicate scaling rules
or assessment instruments to enable the DU to assess the coverage of his use by scaling 25
the determinants of exposure. Scaling and related tools are described in Part I of the
practical guide, chapter 7.7.
In the following example the scaling procedure related to environmental exposure is
illustrated:
A manufacturer/registrant calculates the predicted environmental concentration of his
substances in surface water for the following operational conditions (OC) and risk management measures using the subsequent equation:
23
FOCUS: Forum for the Co-ordination of pesticide fate models and their USe (http://viso.jrc.it/focus/)
24
https://www.ogp.org.uk/pubs/CHARMManualFeb05.pdf
25
Scaling in this context means the use of simple equations in the ES by which the DU can demonstrate that he
operates within the conditions of the ES provided by the registrant.
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June 2010
Quantity of product, in which the substance of concern is
processed or used per year and site
MES
1000 kg/day
Concentration or fraction of the substance in the product
CES
0,1
Emission factor: the fraction of the substance emitted from the
process or use to wastewater (before abatement)
fwater
0,3
Efficiency of an abatement or control technology that reduces the
emission to air, surface water or land
fabatement
0,95
Removal of the substance in the STP
FSTP
0,95
Duration of emission (e.g. working days per year)
Temission
200 days/year
Water treated in the sewage treatment plant
CAPACITY
2,000 m3/day
Dilution factor in the receiving water body
DILUTION
10
M ES  C ES  f water  (1  f abatement )
 (1  FSTP )
Temission
PEClocal = PECregional +
(see also Example R.16.2)
CAPACITY  DILUTION
The registrant calculates a risk characterisation ratio 26 (RCRES) for surface water for his use
situation at 0.3, i.e. below 1, and concludes that the use is safe.
From the above given relevant determinants (i.e. OC and RMM) the registrant considers the
following determinants likely to vary in other similar uses of DUs:
MES, CES, fwater, fabatement, and Temission
All of the above determinants are considered to be mutually independent.
As all determinants are linear with respect to exposure level, the following equation for
scaling is proposed by the registrant to be used by DUs:
RCRDU = RCRES *
M DU C DU f water , DU (1  f abatement , DU ) Temission, ES




M ES C ES
f water , ES (1  f abatement , ES ) Temission , DU
The DU uses the same substance but with different OCs/RMMs for his use:
MDU: 750kg/day
CDU: 0,1
fwater, DU: 0,35
fabatement, DU: 0,98
Temission, DU: 150 days/year
26
82
Risk characterisation ration (RCR) = PEC/PNEC
June 2010
Using the equation for scaling given above, the DU checks whether he is in compliance with
the received ES and whether his use is safe with regard to environmental exposure:
RCRDU = RCRES *
750 0,1 0,35 (1  0,98) 200
= 0,3 * 0,75 * 1 * 1,17 * 0,4 * 1,3 = 0,14
 


1000 0,1 0,3 (1  0,95) 150
The calculated RCR for the use of the DU is < 1. Hence, scaling showed that the specific
conditions of use of the DU are considered safe.
3.4
References
EUSES European Union System for the Evaluation of Substances; Version 2.1 (2008);
http://ecb.jrc.ec.europa.eu/euses/
EU TGD 2003 Risk Assessment Spreadsheet Model;
http://www.envsci.science.ru.nl/cem-nl/products.html
OECD Chemicals Testing – Guidelines;
http://www.oecd.org/department/0,3355,en_2649_34377_1_1_1_1_1,00.html
US EPA OPPT Generic Scenarios;
http://www.epa.gov/oppt/exposure
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June 2010
4
4.1
Appendices
Appendix to Chapter 1: Occupational exposure estimation
Appendix 4.1-1
Examples of publicly available sources for measurement data
Sources
Data
quality*
Comments
EU Risk Assessment Reports
High
Limited
number of
substances
High
Limited
number of
substances
Low
Limited
number of
substances
Low
Limited
number of
substances
Low
Limited
number of
substances
http://ecb.jrc.it/esis/
BGAA-Report 1/99e: Existing commercial chemicals – Exposure at the
workplace
http://www.hvbg.de/d/bia/pub/rep/rep01/pdf_datei/bgar0199/gesa
mt.pdf
Environmental Health Criteria
http://www.inchem.org/pages/ehc.html
SIDS – “Screening Information Data Sets“ AND/OR SIDS Initial
Assessment Reports (SIAR)
http://www.chem.unep.ch/irptc/sids/oecdsids/indexcasnumb.htm
CICAD – “Concise International Chemical Assessment Documents”
http://www.inchem.org/pages/cicads.html
* Data quality:
High: Data are likely to satisfy most of the criteria for exposure estimation and might be sufficient to be used on
their own.
Low: Data are likely to satisfy some of the criteria for exposure estimation but are probably insufficient to be used
on their own.
Appendix 4.1-2
Tier
1
Overview of tier 1 and higher tier estimation tools
Tool
Route of exposure
Resources
Status
ECETOC
TRA
Inhalation and dermal
exposure: quantitative
estimates (single
point values)
Internet: http://www.ecetoc.org/tra (registration
required), tool (MS Excel® spreadsheet) and user
guide. Print: ECETOC 2004, ECETOC 2009TR
New
version
published
August
2009
EMKG
Inhalation exposure
only
MS Excel® spreadsheet available at:
http://www.reachhelpdesk.de/en/Exposure/Exposure.h
tml?__nnn=true. Print: Packroff et al. 2006 (for EMKG
in general, doesn’t address the more recent MS
Excel® spreadsheet)
Unknown
Banding approach
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June 2010
Tier
Higher
Tool
Route of exposure
Resources
Status
RISKOFDERM
calculat
or
Dermal exposure
only: quantitative
estimates (median
and percentiles)
Calculator (MS Excel® spreadsheet) available at:
Version 2.1
Stoffenmanager
Quantitative estimates currently only for
inhalation exposure
Internet: https://www.stoffenmanager.nl/ (registration
required). Report and REACH-related output currently
in Dutch only. Brief online guide at:
https://www.stoffenmanager.nl/Public/Explanation.asp
x. Print: Marquart et al. 2008; Tielemans et al. 2008
http://www.tno.nl/content.cfm?&context=markten&cont
ent=product&laag1=177&laag2=333&item_id=1155&T
aal=2. A guidance document can be downloaded from
the same website. Print: e.g. Marquart et al. 2006;
Warren et al. 2006
Version 3.5
(June
2006)4.0
now
available
For the occupational exposure assessment of metals and inorganic substances the MEASE
tool was developed (online available at: http://www.ebrc.de/ebrc/ebrc-mease.php), based on
the exposure estimation model EASE (see http://www.hse.gov.uk/research/rrhtm/rr136.htm)
and some measured data (see also chapter 1.2.5).
Appendix 4.1-3
Input information needed for tier 1 tools: occupational exposure estimation
Required in
Parameter
Physical state: substance
ECETOC
TRA
EMKG

Available from
Substance-specific data
Physical state: product
Product-specific data
Operating temperature (liquids)

5

Vapour pressure (liquids)



Boiling point (liquids)
5
ES-specific
Dustiness (solids)


SDS/Substance-/product-specific data and
Tables R.14-2 and R.14-8 in ECHA CSA
2008 (Chapter R.14)
Duration of activity
1
1
ES-specific but only very basic data required
2

3

4
Amount of substance/product used
Information on use
Information on RMM
Reference values (e.g. DNELs)

3

4
optional
Notes:
Substance-specific data should usually be available within the framework of the registration process, i.e. these
data are also required for the IUCLID5 datasets.
Product-specific data should usually be available
1
Four duration “bands”in ECETOC TRA and consideration of short-term exposure only (activity < 15 min.
during a full 8 h shift? (yes/no)) in EMKG
2
Only information of the scale is required: small, medium or large and for liquids if more than 1 L/shift is applied
to surfaces.
86
June 2010
3
2
Only information on application on surfaces > 1m (yes/no) is required in EMKG, while more information is
required in ECETOC TRA (indoor/outdoor use, use in mixtures with concentration, industrial vs. professional
activity).
4
LEV (yes/no) and respiratory protection (no, 90% protection or 95% protection) in ECETOC TRA, three
different options in EMKG: general ventilation, engineering controls (e.g. LEV) or containment in EMKG.
5
The operating temperature needs to be known since volatility has to be assessed at the operating temperature.
Appendix 4.1-4
Input information needed for higher tier tools: occupational exposure estimation
Required in
Parameter
Stoffenmanager
RISKOFDER
1
M calculator
Available from
Substance information

Vapour pressure

Molecular weight

Percentage in product

SDS
Physical state

SDS
Vapour pressure (liquids)

SDS
Dustiness (solids)

SDS/Substance-/product-specific
data and Tables R.14-2 and R.14-8
in ECHA CSA 2008 (Chapter R.14)
CAS number
Physical state
Product information

Viscosity
Product-specific data
Dilution with water

ES
Contamination of objects with product

ES
R and S phrases

SDS

Application rate [ L/min]
Product-specific data, may also
depend on the ES
Other information
Level of containment

ES
Information on ventilation

ES
Information on control measures

ES
Duration of activity/task

ES
Frequency of activity/task

ES
Information on use/task

ES
Distance worker-source

ES
Further detailed information

ES
Body parts exposed

ES
Room volume

ES
Direction of application

ES
Length of handle of the tool

ES
87
June 2010
Notes:
Substance-specific data should usually be available within the framework of the registration process, i.e. these
data are also required for the IUCLID5 datasets.
Product-specific data should usually be available.
ES: information on these parameters may be available in the exposure scenario.
1
For the process “Dispersion hand-held tools” (DEO unit 3) as an example (requirements for other processes
differ)
4.2
4.2.1
Appendix to Chapter 2: Consumer exposure estimation
Default values
Body weight
The body weight can be assumed to be 70 kg for adult males and 60 kg for adult females
(see also Appendix R.15-4 (“Data references”) of ECHA CSA 2008). Bremmer et al. (2006)
derive slightly different values of 74 kg for males and 61 kg for females with 65 kg taken as
the default value for adults in general in the ConsExpo software (see Chapter 2.2.3 for
details). ConsExpo uses a default body weight for children of 8.69 kg (age 10.5 months) in a
specific post-application scenario of pest-control products. Default body weight values for
children of different age groups are given in Bremmer et al. (2006).
Skin surface area
Appendix R.15-4 (“Data references”) of ECHA CSA 2008 contains detailed data for the skin
surface area of men and women. The following table summarises the values for some body
parts and the total skin surface area (mean of values for men and women). Values for other
body parts, total skin surface area data for children or sex-specific values can be taken from
Appendix R.15-4 of ECHA CSA 2008. If more detailed information is needed, e.g. data for
specific body parts of children, the references cited in Appendix R.15-4 of ECHA CSA 2008
provide a good starting point.
Appendix 4.2-1
Skin surface areas for adults (Source: ECHA CSA 2008 R15-4)
Body part
Skin surface area (in cm2) for adults
Arms
2 132
Forearms
1 337
Hands (fronts and backs)
Total
88
786
18 150
June 2010
Room volume
Appendix R.15-4 (“Data references”) of ECHA CSA 2008 provides data on the volume of
different room types in the Netherlands (25th percentiles) with some additional data for
Germany (not worst-case).
Appendix 4.2-2
Default values for various room volumes (Source: ECHA CSA 2008 R15-4)
Room volume (in m3)
Room type
Living room
58 (64 in German data)
Unspecified room
30 and 40 (43 for children’s rooms in German data)
Sleeping room
16
Kitchen
15
Toilet
2.5
Bathroom
10*
* A value of 4 3 is given in Appendix R.15-4 (“Data references”) of ECHA CSA 2008. The most recent version of
the source (the ConsExpo “General Fact Sheet”; Bremmer et al. 2006) contains the value used here, which is
also considered more meaningful.
If more detailed information is needed, the report by Bremmer et al. (2006) provides a good
starting point with some additional values.
4.3
Appendix to Chapter 3: Environmental exposure estimation
Appendix 4.3-1
Information requirements for Tier 1 assessment of environmental distribution
Parameter
Description
Source
MOLW
Molecular weight
Technical dossier – Chapter 2
MP
Melting point of substance
BP
Boiling point of substance
VP
Vapour pressure of substance
SOL
Water solubility of substance
KOW
Octanol water partition coefficient of substance
(not inorganics)
Kpsoil
Soil-water partition coefficient. As a default, EUSES
calculates the parameter on the basis of KOW. For inorganic
substances however, Kpsoil should be measured directly,
because other sorption mechanisms, like sorption to mineral
surfaces play in important role.
Technical dossier –adsorptiondesorption screening – Chapter 9
Sediment-water partition coefficient. As a default, EUSES
calculates the parameter on the basis of KOW. For inorganic
substances however, Kpsed should be measured directly,
because other sorption mechanisms, like sorption to mineral
surfaces play in important role.
Technical dossier – adsorptiondesorption screening – Chapter 9
Kpsed
See also Section R.16.4.3.3
89
Kpsusp
June 2010
Solids-water partition coefficient in suspended matter. As a
default, EUSES calculates the parameter on the basis of
KOW. For inorganic substances however, Kpsusp should be
measured directly, because other sorption mechanisms, like
sorption to mineral surfaces play in important role.
Technical dossier – adsorptiondesorption screening – Chapter 9
Biodegradability
Results of screening test on biodegradability. Not relevant for
inorganic substances.
Ej,local
Local emission to compartment j (j: water, air, soil). May be
based on fraction of main source (Fmainsource) and number
of emission days (Temission), M/I_volume, and release
fractions
Release estimation based on
use scenario
Regional emission from source i to compartment j (j: water,
air, soil)}
Release estimation based on
exposure scenario
Eij,regional
See also Section R.16.4.4.4,
R.16.4.4.5, R.16.4.4.7
See Section R.16.2
See Section R.16.2
Appendix 4.3-2
Output EUSES: Predicted environmental concentrations (PECs)
PEC
Parameter
Destination
PECstp
Concentration in the aeration tank of the
sewage treatment plant
Assessment of whether the substance may
inhibit processes in the STP
PEClocal.air,ann
Annual average local PEC in air (total)
–
PEClocal.water
PEC in surface water during episode
Risk assessment fresh water
PEClocal.water,ann
Annual average local PEC (dissolved)
Secondary poisoning
PEClocal.water,marine
PEC in marine water during episode
Risk assessment marine water
PEClocal.water,ann,
marine
Annual average local PEC in marine
surface water (dissolved)
Secondary poisoning
PEClocal.sed
PEC in sediment
Secondary poisoning
PEClocal.sed,marine
PEC in marine sediment
PEClocal.agric,30
Local PEC in agricultural soil (total)
averaged over 30 days
Risk assessment terrestrial environment
PEClocal.agric,180
Local PEC in agricultural soil (total)
averaged over 180 days (to calculate
concentration in crops)
Secondary poisoning
Indirect exposure of humans
PEClocal.grass,180
Local PEC in grassland (total) averaged
over 180 days
Secondary poisoning
PECreg.water,tot
Regional PEC in surface water (total)
Secondary poisoning
PECreg.seawater,tot
Regional PEC in seawater (total)
Secondary poisoning
PECreg.air
Regional PEC in air (total)
–
90
June 2010
PECreg.agric
Regional PEC in agricultural soil (total)
Secondary poisoning
Indirect exposure to man
PECreg.natural
Regional PEC in natural soil (total)
Secondary poisoning
PECreg.ind
Regional PEC in industrial soil (total)
–
PECreg.sed
Regional PEC in sediment (total)
PECreg.seased
Regional PEC in seawater sedim. (total)
Appendix 4.3-3
Example of an environmental exposure calculation with EUSES (taken from RIP 3.2.2 REFERENCE TGD – PART D)
91
92
June 2010
June 2010
93
94
June 2010
June 2010
95
96
June 2010
June 2010
97
98
June 2010

REACH Practical Guide on Exposure Assessment and

Transcription

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